Eh. Not every game will get the upgrade to PS5 so they'll probably keep it another year or so.
Hmm, what do you mean by "keep it"? I think they will try and get rid of stock this fiscal year.
Every game going forward will be forward compatible and should feature PS5 boost mode without actually being ported to PS5. Pro support in game will still be a thing but based on the current userbase, not because sony continues to manufacture the hardware
I think it makes more sense Pro is discontinued in the coming months and they have less convolution in the retail and manufacturing space. Its already a more niche selling model and with PS4 sales dwingling it doesn't really make sense to push $299 outdated machine in 2021, it probably would't even sell at that price but lets see.