Core Class Redirect doesn't work when converting from a C++ class to a BP

The Export map will properly be updated but the creation of the import will fail with SourceIndex == INDEX_NONE

From MarcA:

 I'm guessing the import source index is always none for native classes because the linker isn't responsible for loading the dependent packages and even though technically the asset is available if you make it be there, I'm not sure the linker is going to be willing to just go along with it ... but maybe

• Create a custom C++ actor (MyActor)
• Create a level with an instance of MyActor
• Create a BP that derivates from MyActor-> MyActorBP
• Add a ClassRedirects to the project from MyActor to MyActorBP

+ClassRedirects=(OldName="/Script/GymCore.MyActor",NewName="/Game/MyActorBP.MyActorBP_C",InstanceOnly=true, OverrideClassName="/Script/Engine.BlueprintGeneratedClass")

• The Export map will properly be updated but the creation of the import will fail with SourceIndex == INDEX_NONE