The chances of a new Castlevania being revealed at E3 are about as high as The Last Guardian being re-revealed for the PS4 and released later this year.
I think the chances of seeing TLG at E3 this year is actually bigger than ever. Or possibly TGS. That doesn't mean the chances are big at all, but if the game is indeed still in development, they have now had plenty of time to do something for the PS4. Last year was probably too early, but this year? I think it could happen. People are really treating TLG like it's some kind of impossible joke that could not possibly ever happen. I find that funny, especially since we've seen arguably bigger things, like FFXV, resurface after years.
Besides, what is Team ICO even doing if not working on at least
something?