Hm, yeah! That's great observation! You've convinced me.
I was nursing the idea Batman v.2 might be Harvey Dent, but Robinson has been clear that he has strict instructions not to unneccesarily duplicate existing Earth-1 characters. So no Lex Luthor of Joker for example. Now it's possible of course that Batman will be an unknown, but Robinson has also made clear his identity will be a secret for a little while, so clearly it's someone we should know.
Rex Tyler might seem an odd choice given he's historically Hourman, but the fact he was mentioned as having bought out Waynetech and its assets is surely a clue Robinson planted early... if it's not Tyler it's someone close to him.
You've sold me.
James Robinson says "This isn't some new person coming in to be Batman. This is definitely a part of Batman lore." Yes, Hourman is technically a part of Batman lore since both were in the JSA, but I suspect it's not.
Now let's consider the above comment that "Robinson has been clear that he has strict instructions not to unneccesarily duplicate existing Earth-1 characters. So no Lex Luthor of Joker for example." I also think it should be a character previously established as being on one of the previous Earth 2 incarnations. With those things in mind...I got nuthin' LOL