Given how important Naughty Dog has become to Sony, its very likely that they have two teams that are big enough to handle two big projects at once.
I do think that maybe it will get the first game treatment.But I still thats very likely that the game will just release for the PS4 for now and maybe get the Nathan Drake collection treatment(in the sense that it will be ported 2 or 3 years down the PS5 lifecycle).
My (locked) thread about how difficulty should be a decision for the developers, not the gamers.
https://gamrconnect.vgchartz.com/thread.php?id=241866&page=1