Installing RuntimeCompilation package changes versions of published assemblies

[ygoe]

In my ASP.NET Core MVC application, the publish directory for the Release build contains DLLs that have the version number 3.1.0:

• Microsoft.AspNetCore.Razor.Language.dll
• Microsoft.CodeAnalysis.Razor.dll
• Microsoft.Extensions.DependencyModel.dll (even at version 2.1.0)

After installing the package Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation, those file versions change to 3.1.6.

Also, the file Microsoft.DotNet.PlatformAbstractions.dll goes away and two others appear. Additionally, a new folder "refs" appears with 7 MB and 255 .dll files!

What do these changes mean? Why do I get more current files by installing that package? Why were they outdated before? And what good are these 255 additional published files?

I'd like to have runtime recompilable views in the development environment but not see any of those additional bits or behaviour in production. How can I achieve that?

Edit: Might be related to this: dotnet/sdk#10012