I'm thinking launch holiday 2020 too. In terms of launch/first next gen game for each Sony studio and there likely third party partnerships:
Launch:
Insomniac: Ratchet and Clank - good action platformer game that appeals to all ages. Franchise isn't getting dated thanks to the gameplay focusing on guns and action, and the remake of the first game was popular, so I think it's a good fit for launch.
Guerilla: Horizon 2 - will be nearly four years since the first game in late 2020. Think that is just enough time for the sequel. Could be a big system seller
Then after that, the next projects I see in terms of exclusives
First Party:
Santa Monica: God of War 2
Naughty Dog: New IP
Media Molecule: New IP
Polyphony: Gran Turismo 7 (with big offline career mode making a return)
Japan Studio: Two new IPS, one regular, one VR
Sucker Punch: Ghosts of ________. Might be Tsushima 2, but I have a small feeling they might move the setting around as a theme, like Ass Creed
Sony Bend: depends on Days Gone sales. if not, new IP or Socom reboot
PixelOpus: new IP, AA
London: god knows.
San Diego: MLB
San Diego 2: Sony's new studio that is rumoured to be working alongside a major first party studio. Most likely continuing the Uncharted franchise with Naughty Dog overseeing
And Sony's partners:
Insomniac: Spidey 2
Bluepoint: going to keep pumping out classic remasters
Gen Design: think this will be exclusive. Looking forward to seeing what Ueda has come up with now
From Software: unsure about the likelihood, but I think the desire will be there from Sony at least to get an exclusive from them, and they have a good relationship with Miyazaki now
Supermassive: another game in the vein of Until Dawn
Quantic Dream: have a feeling they might go multiplatform next gen, but if not we know what kind of thing to expect
