AssemblyLoadContext with assembly unloading is not at all compatible with .NET Framework 4.X, which can be a pain if you want to gradually migrate stuff.
Also it does not have anywhere near the same level of isolation, which is part of what System.Web.dll was using them for. Would it be possible to it in a system.Web.dll port? Certainly, but you would be changing the semantics enough that some applications would notice the difference, and probably not in a good way.
yeah I mean unloading is not even that good without a .net core 3.0 preview.
I think that in 5-10 years new stuff will emerge based on AssemblyLoadContext, maybe even some kind of OSGi just a little bit easier. Some examples are really promising and AssemblyLoadContext does not have the same problems as Java solutions. (duplicate Class Files, etc...)
the only thing that is missing is some kind of security related stuff.
Also it does not have anywhere near the same level of isolation, which is part of what System.Web.dll was using them for. Would it be possible to it in a system.Web.dll port? Certainly, but you would be changing the semantics enough that some applications would notice the difference, and probably not in a good way.