I wouldn’t get my hopes up for anything LZA related. Fans have already pointed out the absence of a Pokémon Presents watch this age like sour milk and I would expect this to be a smaller-end replacement to that, similar to how Partner Showcases have been replacements for larger Nintendo Directs a couple times.
Edit: I’m almost certain this might have something to do with Pokémon Masters, especially after what happened with that game and the last August Pokémon Presents. Not only did Nemona & Scream Tail, and Prof. Oak & Nidorino, come out in the game today but we also have the 5th anniversary update coming up, projected for the end of August like usual.
While Z-A is by no means confirmed to be here, there is 0 reason to expect Masters to be present at this. Worlds announcements tend to focus on, you know, the stuff at worlds. Last year, for example, they showed off Paradox Pokemon in the TCG, Meowscarada/Blaziken/Mimikyu coming to Unite and of course the trailer that showed off new "competitive" moves and pokemon for the DLC.
Masters, even ignoring that it already announced its celebration stuff separately, is just...not even remotely in this wheel-house. It's in its own mobile house with Sleep and Cafe
Things I think would be more likely, though itself not guaranteed:
-New characters for Unite. I believe the test server already tells us what those will be, but shhh. It's a surprise. Act surprised.
-For the TCG, since Pocket was demoed at the show floor they could announce a proper release date or at least when beta might start.
-Alternatively, if they want to keep it to the "proper" TCG we know "Owner's Pokemon" are coming back, which feels like something they could spin as its own mechanic this go around. That puts it in a similar vibe to announcing Tag Teams, ex's, paradoxes, etc.. They could also tease the return of Mega Evolution but we're still several sets from those being relevant, regardless of when Z-A comes out.
-Go wasn't at last years and generally doesn't get "big" announcements. Last year's bigger announcement (Paldean Pokemon) already got rolled into the Presents proper. But we know Dynamax is like
really imminent and would be a significant new feature, especially if they tied it to the roll out of Gen 8 Pokemon. Seems a good a time as any to announce it here
-It's honestly kind of hard to gauge how they'll talk about Z-A, especially since it wont be relevant for competitive at all. 2018 I think didn't have anything notable about Let's Go, but I guess there also wasn't really anything to talk about. BDSP & L:A didn't have a Worlds to even begin to be snubbed at. Personally I feel like the first actual footage of the game would probably want a proper presentation...I think if we hear anything about Z-A, it might be more akin to a date of when more information will drop.