I think for Cates the Herald Thor speculation is most likely.

David Nakayama is likely there due to being a regularly-commissioned artist for the line (among many others, he did the package art for all the Age of Apocalypse releases, and the Strong Guy Deadpool wave, off the top of my head) and not due to him doing a random variant cover. Can't speak for Cates though - maybe some tease of another Venom wave with some Let There Be Carnage figures? 

Doubt they'll show anything new, possibly confirming some standing rumors, especially regarding the TB Legends. My only hope right now is that we see something about US Agent.

Is that a joke? I’m assuming that’s sarcasm, but in case you’re serious, no, there isn’t. What percentage of Avengers or X-Men membership is non-white? What percentage is non-male, for that matter? There are hundreds of prominent X-Men characters, and you would assume mutation would occur more or less equally across racial lines. Can you name five who are black off the top of your head? Ten? Of the most prominent three, one is of completely indistinguishable race and was retroactively determined to be African, and one has a variety of European features to play down her blackness. I’m impressed. Every time I think your mind couldn’t possibly get any smaller, you prove me wrong. You have to have equal rights to exchange them for anything. Look, nobody likes “tokenism”, but while small-minded, insecure white men continue to run the show, there aren’t a lot of paths to equal rights. This, exactly. Thank you for being a voice of reason here. It’s interesting to note that Marvel has still yet to have the courage to cast any major character from the comics in a way that’s inconsistent with their original appearance, and the MCU is still 60+% white. It’s not exactly a case study in either the unthinkable tragedy of tokenism or the triumph of righteous diversity.

That's my feeling as well.