I'm not sure what they're even going to cover. They covered just about everything from the Glavenus trailer with the developer discussion, they had all of those Game Informer bits about behind-the-scenes stuff, and we'd have seen a new trailer by now if there was going to be one (and the last trailer wasn't that long ago).Two and a half hours from this post, Capcom is doing an Iceborne panel at Comic-Con, but it remains to be seen if anything new will be revealed. I don't think it's being streamed in any way.
It'd have to be something new but not important enough to warrant its own trailer, like revealing Giginox or some other returning non-flagship and not much else.