diff --git a/src/Umbraco.Core/Models/ContentType.cs b/src/Umbraco.Core/Models/ContentType.cs
index 9c21cf5e80..1e011bbd07 100644
--- a/src/Umbraco.Core/Models/ContentType.cs
+++ b/src/Umbraco.Core/Models/ContentType.cs
@@ -13,7 +13,7 @@ namespace Umbraco.Cms.Core.Models
     /// </summary>
     [Serializable]
     [DataContract(IsReference = true)]
-    public class ContentType : ContentTypeCompositionBase, IContentTypeWithHistoryCleanup
+    public class ContentType : ContentTypeCompositionBase, IContentType
     {
         public const bool SupportsPublishingConst = true;
 
diff --git a/src/Umbraco.Core/Models/IContentType.cs b/src/Umbraco.Core/Models/IContentType.cs
index e3fd83fcd3..4d693f9a50 100644
--- a/src/Umbraco.Core/Models/IContentType.cs
+++ b/src/Umbraco.Core/Models/IContentType.cs
@@ -4,19 +4,6 @@ using Umbraco.Cms.Core.Models.ContentEditing;
 
 namespace Umbraco.Cms.Core.Models
 {
-    /// <summary>
-    /// Defines a content type that contains a history cleanup policy.
-    /// </summary>
-    [Obsolete("This will be merged into IContentType in Umbraco 10.")]
-    public interface IContentTypeWithHistoryCleanup : IContentType
-    {
-        /// <summary>
-        /// Gets or sets the history cleanup configuration.
-        /// </summary>
-        /// <value>The history cleanup configuration.</value>
-        HistoryCleanup? HistoryCleanup { get; set; }
-    }
-
     /// <summary>
     ///     Defines a ContentType, which Content is based on
     /// </summary>
@@ -70,5 +57,11 @@ namespace Umbraco.Cms.Core.Models
         /// <param name="newAlias"></param>
         /// <returns></returns>
         IContentType DeepCloneWithResetIdentities(string newAlias);
+
+        /// <summary>
+        /// Gets or sets the history cleanup configuration.
+        /// </summary>
+        /// <value>The history cleanup configuration.</value>
+        HistoryCleanup? HistoryCleanup { get; set; }
     }
 }
diff --git a/src/Umbraco.Core/Models/Mapping/ContentTypeMapDefinition.cs b/src/Umbraco.Core/Models/Mapping/ContentTypeMapDefinition.cs
index bacab0b7cf..c45af69b23 100644
--- a/src/Umbraco.Core/Models/Mapping/ContentTypeMapDefinition.cs
+++ b/src/Umbraco.Core/Models/Mapping/ContentTypeMapDefinition.cs
@@ -131,7 +131,7 @@ namespace Umbraco.Cms.Core.Models.Mapping
             MapSaveToTypeBase<DocumentTypeSave, PropertyTypeBasic>(source, target, context);
             MapComposition(source, target, alias => _contentTypeService.Get(alias));
 
-            if (target is IContentTypeWithHistoryCleanup targetWithHistoryCleanup)
+            if (target is IContentType targetWithHistoryCleanup)
             {
                 MapHistoryCleanup(source, targetWithHistoryCleanup);
             }
@@ -147,7 +147,7 @@ namespace Umbraco.Cms.Core.Models.Mapping
                 : _fileService.GetTemplate(source.DefaultTemplate));
         }
 
-        private static void MapHistoryCleanup(DocumentTypeSave source, IContentTypeWithHistoryCleanup target)
+        private static void MapHistoryCleanup(DocumentTypeSave source, IContentType target)
         {
             // If source history cleanup is null we don't have to map all properties
             if (source.HistoryCleanup is null)
@@ -209,7 +209,7 @@ namespace Umbraco.Cms.Core.Models.Mapping
         {
             MapTypeToDisplayBase<DocumentTypeDisplay, PropertyTypeDisplay>(source, target);
 
-            if (source is IContentTypeWithHistoryCleanup sourceWithHistoryCleanup)
+            if (source is IContentType sourceWithHistoryCleanup)
             {
                 target.HistoryCleanup = new HistoryCleanupViewModel
                 {
diff --git a/src/Umbraco.Core/Services/EntityXmlSerializer.cs b/src/Umbraco.Core/Services/EntityXmlSerializer.cs
index c91f536b38..00f9dc2a18 100644
--- a/src/Umbraco.Core/Services/EntityXmlSerializer.cs
+++ b/src/Umbraco.Core/Services/EntityXmlSerializer.cs
@@ -511,7 +511,7 @@ namespace Umbraco.Cms.Core.Services
                 genericProperties,
                 tabs);
 
-            if (contentType is IContentTypeWithHistoryCleanup withCleanup && withCleanup.HistoryCleanup is not null)
+            if (contentType is IContentType withCleanup && withCleanup.HistoryCleanup is not null)
             {
                 xml.Add(SerializeCleanupPolicy(withCleanup.HistoryCleanup));
             }
diff --git a/src/Umbraco.Infrastructure/Packaging/PackageDataInstallation.cs b/src/Umbraco.Infrastructure/Packaging/PackageDataInstallation.cs
index f0bca5f1ea..a45c26a44d 100644
--- a/src/Umbraco.Infrastructure/Packaging/PackageDataInstallation.cs
+++ b/src/Umbraco.Infrastructure/Packaging/PackageDataInstallation.cs
@@ -890,7 +890,7 @@ namespace Umbraco.Cms.Infrastructure.Packaging
             UpdateContentTypesPropertyGroups(contentType, documentType.Element("Tabs"));
             UpdateContentTypesProperties(contentType, documentType.Element("GenericProperties"));
 
-            if (contentType is IContentTypeWithHistoryCleanup withCleanup)
+            if (contentType is IContentType withCleanup)
             {
                 UpdateHistoryCleanupPolicy(withCleanup, documentType.Element("HistoryCleanupPolicy"));
             }
@@ -898,7 +898,7 @@ namespace Umbraco.Cms.Infrastructure.Packaging
             return contentType;
         }
 
-        private void UpdateHistoryCleanupPolicy(IContentTypeWithHistoryCleanup withCleanup, XElement? element)
+        private void UpdateHistoryCleanupPolicy(IContentType withCleanup, XElement? element)
         {
             if (element == null)
             {
diff --git a/src/Umbraco.Infrastructure/Persistence/Repositories/Implement/ContentTypeRepository.cs b/src/Umbraco.Infrastructure/Persistence/Repositories/Implement/ContentTypeRepository.cs
index 9e2f0257b6..9859b1e69a 100644
--- a/src/Umbraco.Infrastructure/Persistence/Repositories/Implement/ContentTypeRepository.cs
+++ b/src/Umbraco.Infrastructure/Persistence/Repositories/Implement/ContentTypeRepository.cs
@@ -302,7 +302,7 @@ namespace Umbraco.Cms.Infrastructure.Persistence.Repositories.Implement
         {
             // historyCleanup property is not mandatory for api endpoint, handle the case where it's not present.
             // DocumentTypeSave doesn't handle this for us like ContentType constructors do.
-            if (entity is IContentTypeWithHistoryCleanup entityWithHistoryCleanup)
+            if (entity is IContentType entityWithHistoryCleanup)
             {
                 ContentVersionCleanupPolicyDto dto = new ContentVersionCleanupPolicyDto()
                 {
diff --git a/src/Umbraco.Infrastructure/Runtime/CoreRuntime.cs b/src/Umbraco.Infrastructure/Runtime/CoreRuntime.cs
index 5866589c6f..6e01d2b260 100644
--- a/src/Umbraco.Infrastructure/Runtime/CoreRuntime.cs
+++ b/src/Umbraco.Infrastructure/Runtime/CoreRuntime.cs
@@ -169,9 +169,6 @@ namespace Umbraco.Cms.Infrastructure.Runtime
             // Acquire the main domain - if this fails then anything that should be registered with MainDom will not operate
             AcquireMainDom();
 
-            // TODO (V10): Remove this obsoleted notification publish.
-            await _eventAggregator.PublishAsync(new UmbracoApplicationMainDomAcquiredNotification(), cancellationToken);
-
             // Notify for unattended install
             await _eventAggregator.PublishAsync(new RuntimeUnattendedInstallNotification(), cancellationToken);
             DetermineRuntimeLevel();
@@ -210,9 +207,6 @@ namespace Umbraco.Cms.Infrastructure.Runtime
                     break;
             }
 
-            // TODO (V10): Remove this obsoleted notification publish
-            await _eventAggregator.PublishAsync(new UmbracoApplicationComponentsInstallingNotification(State.Level), cancellationToken);
-
             // Initialize the components
             _components.Initialize();
 
diff --git a/tests/Umbraco.Tests.Integration/Umbraco.Infrastructure/Packaging/PackageDataInstallationTests.cs b/tests/Umbraco.Tests.Integration/Umbraco.Infrastructure/Packaging/PackageDataInstallationTests.cs
index cc446e0ea6..e7ddd13e0b 100644
--- a/tests/Umbraco.Tests.Integration/Umbraco.Infrastructure/Packaging/PackageDataInstallationTests.cs
+++ b/tests/Umbraco.Tests.Integration/Umbraco.Infrastructure/Packaging/PackageDataInstallationTests.cs
@@ -776,7 +776,7 @@ namespace Umbraco.Cms.Tests.Integration.Umbraco.Infrastructure.Packaging
             // Act
             var contentTypes = PackageDataInstallation
                 .ImportDocumentType(withoutCleanupPolicy, 0)
-                .OfType<IContentTypeWithHistoryCleanup>();
+                .OfType<IContentType>();
 
             // Assert
             Assert.Multiple(() =>
@@ -795,7 +795,7 @@ namespace Umbraco.Cms.Tests.Integration.Umbraco.Infrastructure.Packaging
             // Act
             var contentTypes = PackageDataInstallation
                 .ImportDocumentType(docTypeElement, 0)
-                .OfType<IContentTypeWithHistoryCleanup>();
+                .OfType<IContentType>();
 
             // Assert
             Assert.Multiple(() =>
@@ -817,11 +817,11 @@ namespace Umbraco.Cms.Tests.Integration.Umbraco.Infrastructure.Packaging
             // Act
             var contentTypes = PackageDataInstallation
                 .ImportDocumentType(withCleanupPolicy, 0)
-                .OfType<IContentTypeWithHistoryCleanup>();
+                .OfType<IContentType>();
 
             var contentTypesUpdated = PackageDataInstallation
                 .ImportDocumentType(withoutCleanupPolicy, 0)
-                .OfType<IContentTypeWithHistoryCleanup>();
+                .OfType<IContentType>();
 
             // Assert
             Assert.Multiple(() =>