An Earth-2 Barry Allen might be a possibility, but then if this was the case would there not be an Earth-1 Jay Garrick?
One of the realities of the two earths in Comics is that characters are not necessarily duplicated between worlds, and that's a very sensible thing to show. I don't think Zoom is a Barry Allen, despite having what appears to be the same costume, and while it may be that Harrison Wells-2 is a red herring meant to have us make an assumption it is he I can't believe they would introduce him without him being a very strong importance to the plot. Wells-2 built STAR Labs, it makes some sense that if he isn't Zoom himself then he is at least directing him...
Black racer of the new gods?