Based on my reading of the link you provided I don't believe support for GVT-g has been removed.
You can see the GVT-Linux repository is also still receiving commits: https://github.com/intel/gvt-linux
You can see the GVT-Linux repository is also still receiving commits: https://github.com/intel/gvt-linux
As for GVT-g and Xe, according to a post in this[0] issue by one of the Intel devs, Rocket Lake (Xe) is not getting support and only does GVT-d.
Also in the same issue, someone pointed out that Intel themselves have states as much here[1].
I hope I am proven wrong in the end and GVT-g comes to then entire Xe and ARC lineup. Intel's communication on this matter has been...lacking.
0: https://github.com/intel/gvt-linux/issues/190
1: https://www.intel.com/content/www/us/en/support/articles/000...
Makes sense as in servers you probably want static partitioning anyways, but for desktop it was perfect.
It may be that they're changing internal APIs used for device mediation which wouldn't surprise me given both AMD and Nvidia use SR-IOV but only Intel uses GVT-g.