Yeah, I fucking hate Thor (both of them) and even I thought that was actually a good trailer. Or perhaps just the part of getting rid of Midgar, which was always the super boring part of the first two movies anyway. Saying that it's "too much like Guardians" is silly, because combining these movies together is entirely the point of the whole MCU. So either Guardians needed to become boring like Thor, or Thor needed to become less boring like Guardians. I think we all know which one of those is a good decision and which one isn't.
I mean, these are just vehicles to make money, not be artistic masterpieces. And combining them into one, probably not as interesting but still, universe was always the game here. You can't resent that now if you were rooting for the "Phase" system before (not saying you did, just general). And with Marvel I don't think that is a problem, because let's face it: all of their characters are kind of shitty as it is. Only Iron Man is mildly interesting because he's actually just human.
With DC however, it is a huuuuuge problem because Superman is an optimist (so color and bright and what not) and Batman is a pessimistic realist (dark & gritty). I mean, one is the day, the other is the night, combining those takes a far more analytical approach than just shoving them into one movie. But apparently nobody at WB or DC realizes that, or something.