I don't think Sony is going to announce much stuff. They're going to reveal more demo's and gameplay. We still need first official look into Spiderman, Death Stranding, TLOU 2( Despite here, I think we won't see any gameplay, maybe a new Teaser).
I think they are going to show a lot of Detroit, Days Gone, God of War and 3rd Party stuff like Battlfront 2 Coop mission, CoD WWII and Destiny 2. With along these games (don't count TLOU2) and with few new announcements and indies, the show is fully booked.
We shouldn't expect any big megatons, the only possible new announcement could be Sucker Punch's new IP, but that's it.
So this E3, more Gameplay and less announcements.