Yeah late April is probably the best bet. It makes sense if you consider how movies like Mission Impossible 6, Jurassic World 2, Skyscraper, Pacific Rim 2, etc are getting little to no attention on movie sites despite all having their trailers out. There's just too much to talk about they're getting drowned out in all the more immediate releases.
I'm honestly glad The Predator didn't release a trailer at the super bowl. Cinemacon can't get here soon enough, though.