Could be; it's an interesting behind-the-scenes observation. But then, I wonder if that distinction ultimately matters to the film's success?The thing is, we might think some of this stuff is CGI when it really isn't. Since this stuff is filmed digitally, they have gotten really good at blending everything together. Unfortunately, that means the real stuff that is probablty slightly digitally enhanced, matches really well with the actual CGI stuff, making us overestimate the ratio. Remember how much of the Star Wars Prequels is models, but it all blends together as "too much CGI".
When people say "too much CGI," they're essentially saying they don't believe what they're seeing. Nobody said there was too much CGI in Gollum in LOTR, because we bought it. If someone said a Prequels model looked too CG... well, then one way or another, it wasn't a convincing shot.
In the IndyDD trailer, I don't buy that the characters are standing on the roof of a moving train. [To be fair, I rarely do.] Yet I did buy that precise situation in Last Crusade. Did I buy the scene in LC because it was filmed practically, and do I not buy the trailer shots because they're CG, or even just slightly digitally enhanced? Maybe, and if so, that's worth discussing from a filmmaking process standpoint. But even if what we're seeing in the trailer is "the real stuff" and our eyes are tricking us... regardless, our eyes are being tricked by something in one and not the other.
Hopefully HMSwolfe is right that these are compression issues or unfinished effects, and it'll look more believable in the theater. As it stands, I agree with blewis17 that a worrying amount of action in the trailer comes across as superhero-ish.