Ubisoft already announced they have five 2020 games, all of which will be on next-gen systems in addition to current gen systems. Watch Dogs Legion, Rainbow Six Quarantine, and Gods & Monsters are already confirmed to be on next-gen consoles, the other two are rumored to be Assassin's Creed Vikings and Just Dance 2021.
As for 1st/2nd party, nothing confirmed yet besides Hellblade and Halo 5, though the Series X trailer strongly hints that there will be a Forza game available on launch, probably Horizon 5, since Motorsport 8 is still early development. I wouldn't be surprised if they have a 2nd party exclusive available on launch as well, something from Japan maybe, if they want to make any sales headway whatsoever in Japan early gen. MS did say in recent interviews that they were interested in partnering with JP devs on 2nd party exclusives.
Microsoft will likely want to have a steady stream of games throughout 2021, 22, etc. Before they had issues releasing games outside the holiday period. At least more than one decent size game.
As for the launch, a Forza game was a given as it's the biggest racing sim franchise.
A game directed towards Japan would be smart. Though it would take releasing several games to have any chance of it not bombing.