Sony revealed the PS5 logo at an event not strongly associated with gaming and the whole world knows about it. I'm sure they could easily skip E3 and showcase the PS5 in their own event, either a State of Play or a live event similar to the ones that revealed the PS4 and later the PS4 Pro.
Pretty much this. E3 needs Sony more than Sony needs it tbqh.
They could just have a half year PSX if they really needed a live event.