Yeah, at this point, I'm leaning towards Zoom being the Earth-2 Barry Allen as well, which is kind of funny since I thought last season Harrison Wells/Eobard Thawne/Reverse Flash was a future version of Barry, but oh well
Because it certainly seem like much of a coincidence that Zoom's costume is pretty much Barry's suit done in all black and gray. Moreover, let's not forget the vision of future Barry had when he saw himself in behind bars at Iron Heights. What if that's because Zoom frames Barry for a crime he didn't commit and the reason Zoom could pull that off is because, if he's the Earth-2 Barry, they would both have the same DNA.
The other possibility is that it's the Earth-2 Henry Allen, which could explain why John Wesley Shipp seemed to leave the show so abruptly the way he did during the season premiere.