Wonder Woman also did amazing numbers before WW84 made the lowest opener for DC
Since the first movie, there's no trust left in DC, the DCEU is already r making this movie a zombie, and WB hasn't yet learnt from Ezra fiasco sheen they decided to persist with Amber.
The only real question is if this will be buffet flop then The Flash or The Blue Beetle?
It's going to be fighting upstream for sure, audiences appear to be losing interest in yet-another-superhero movie. Jason Momoa has alot of star draw, so I'm not sure if that will even out. There actually hasn't been much of a media campaign at all for this release, so thats not a great sign, it means the studio isn't confident and is hedging its bets by not wasting money on media.
The casting controversy probably will hurt it too, but maybe enough people will be interested in it that it works as advertising and drawing in more people.
Overall I'd say the expectations are cautious right now
Trailer for a trailer is a pattern that started a few years ago. It's annoying and I hate it. The worst is when they put those 5 second clips at the beginning of YouTube trailers announcing a trailer is coming up.