Outside of Sucker Punch which first party developers are overdue for a reveal? I can see this E3 mostly just being updates on games we already know. Like release dates for God Of War, Detroit, and Dreams and new footage and details for Spider-Man and Days Gone. I don't think we're gonna get Death Stranding and Last Of Us 2 gameplay maybe at PSX but those games have been development for around a year to a year and half.
So yeah I can see them holding back for PSX simply due to not being ready.