The only noteworthy moment in Endgame's trailer was the SPOILERS, reveal that Ant-Man will appear. Having seen the Wasp movie, I thought the ending would mean otherwise, so that genuinely surprised me (and the dialogue in Ant-Man's moment was funny enough unlike the rest of the generic trailer lines). Also the fact that MAJOR INFINITY WAR SPOILERS FOLLOW the ending made it clear that only original Gen 1 Avengers survived the cosmic finger-snap, which Ant-Man is not.
Even my easy to please friend called it "Nothing special."
But there's reasons for why Endgame was snoresville. Marvel either elected to not show any key moments (Ant-Man aside) to save for the next trailer and the feature, or there's only so much that has been shot and edited at this point (there wasn't even one action scene shown which I would imagine take the most effort to pull off).
If it were up to me, I wouldn't have even shown the trailer. It's obvious based on how the last one ended (and because every year has to have more Mahvel Supa Hero movies than the last) that Endgame was coming, and they didn't even give the (meh) 2nd trailer for Captain Marvel any room to breathe. It would've been better if they held off on any marketing for Endgame until Captain Marvel released, to help build up more suspense/speculation.
Infinity War was the best superhero movie in years, and the best Marvel movie since the first Avengers, so I'm seeing it no matter how badly Disney might crash the hype train leading up to late whenever it does release.