The ship in the teaser doesn't even look like the NX-01. Proportions are wrong, nacelles are differently shaped, support pylons taper in the wrong direction and have that funky bend in them, no outriggers on top of the primary hull, etc, etc.
No reason to think it's anything other than some random new class of ship designed for this movie, just as they did with several never before seen classes in the last one.
Even so, it's a promising looking shadow. It has a much wider stance than the nu-1701 and the nacelles don't look childishly "ample." Dare to dream of an eventual refit in the nu-Universe?
Old-Spock is there, so he could certainly pass along some ship design advances. He already gave up the formula for transwarp beaming.