Game streaming is something MMOs and some other online competitive games have problem with.

WoW was on GFN beta twice and Blizzard wasn't happy, even banned some players that were playing it and took down the game from GFN. Game streaming prevents the game from analyzing what software is active while you are playing the game - anti-cheat/anti-bot systems.

GFN is trying to be as generic as possible so either they make some API that game makers could use or most such games will stay away from game streaming. Other option is a sort of white labeled Google Stadia, assuming it won't end in the graveyard. They already started doing this so they could make a custom clients for specific game - and thus providing extra data MMO anti-cheat would require (this could even allow those system to be integrated into streaming client itself).

And DX12/Metal FF14 client updates are rather inevitable but that likely will be planned alongside some other legacy system devastation....