I don't expect this will be much more than the next "evolution" of Playgrounds.
I don't think Apple would even want/be willing to support anything other than Swift, and probably only iOS/Catalyst development. Anything complex with multiple languages (Objective-C, Swift, C, C++ and/or any scripting) would probably not be supported, so there wouldn't be any chance of "porting" your existing projects to this iXcode.
It might be an evolution towards "coding-as-a-service", which I've been expecting: https://macintouch.com/community/index.php?threads/competiti...
However, your forum post says you believe Apple wants to take the power of the ability to locally compile and sign away from developers. This is unlikely for a number of reasons, one of which is completely breaking all games built using non-SceneKit workflows (basically all of them) along with other apps that depend on outside compilers.