This indeed has been asked dozens of time before, a quick serach on the forums with “GeForce Now” keyword would have showed you literally dozens of threads.
Here is one example, where a devs answered.
I really don’t know all the details, but i think it’s not as easy as you think to get approval for a game to get included on that platform.
It’s not as simple as “let’s test out if it runs and if not we can leave”.
As you can see from Sarno’s response in the thread i posted, they are not completely aversed to this, it’s just a matter of time and ressources for them.
I am sure it will eventually come to this platform, but i personally owuldn’t expect this before release.