Personally I think Media Molecule's new IP is a good bet as they've been saying they will give details soon, maybe Horizon (Guerrilla Games have been vocal and recent leaks seem like the pre-marketing to a reveal, similar to Bloodborne), new gameplay for Uncharted, with release window announcement, the first trailer for Ratchet & Clank, along with a release date. GT7 could be a good bet.
New details and footage for WiLD, Rime, Shadow of the Beast, Until Dawn.
Some new Trailers for The Order and Bloodborne.
Even if Horizon and MM's new IP are unveiled, along with GT7, Ratchet & Clank and Uncharted Sony still has a lot of studios that have been quiet for ages and this year has shown how good Sony have been at getting external partners on board, so I doubt they'd be short on games to reveal throughout next year.
