Sony has done a fantastic job this generation in partnering with third-party developers, particularly Activision and EA. Every year Call of Duty and Destiny make an appearance on Sony's E3 stage, and this year will be no different.
As well as the Activision titles, Star Wars Battlefront II is sure to make an appearance on Sony's stage, with a likely announcement for exclusive and timed DLC.
The outlier here is Red Dead Redemption II. Sony also has a marketing partnership with Rockstar when it comes to the western sequel, so there is a possibility that we see a new trailer at E3. Rockstar generally don't appear at E3 but GTA V remastered was announced on Sony's stage at E3 2014, so an appearance isn't out of the question. Also, when the game was delayed Rockstar said we would see more soon, and E3 seems perfect.
A trailer for Red Dead Redemption II could win E3 for Sony by itself!