I think they've been planning it for a long time. I remember a "huge announcement" was hinted at by nvidia for Linux at a then upcoming CES? might have been Computex. It had been delayed multiple times before and this time covid hit, the announcement was cancelled and I never heard anything more about it.
As far as it getting upstreamed into the kernel assuming that is indeed their plan. Phoronix claimed on 30th August 2020 that a driver for the nintendo switch controller would land in kernel 5.10 and then again on 27th October 2021 that it would land in 5.16 (I assume it did this time). Which I point out to show how difficult this sort of thing is to predict. Additionally nvidia has a lot more work to do in comparison as will nouveau on expanding support.
Of course nvidia have more money to throw at it, but I am not holding my breath.