I won't spoil on Rebirth #1, but having read on the news-sites it is fair to say that this issue is a very faithful recreation of the plot for Infinite Crisis #1, near blow for blow. Right down to the utterly unexpected 'Kal-L' figure on the final pages.
It may be that this is Geoff Johns Formula for writing these big events and he isn't aware he is recycling, not that recycling is necessarily a bad thing, if he is addressing head-on some of the real problems that the last five years have served us then let us commend him on actually caring enough to do so. But as with Infinite Crisis #1 you may well feel that this use of key characters was unneccesary, that it is a case of of raking over old things best left in their context. As with Infinite Crisis there is nothing actually new to be had with Rebirth #1 - there are no new characters or concepts here to usher in this new era, just industrial recycling of familiar old fan-pleasing faces that perhaps don't belong in the present. And I include Wally West in that statement.
And it may well be that it doesn't matter anyway. None of it. Quite clearly the focus has shifted at DC, television and media is where it is at now, everyone will rave about Supergirl, The Flash, Preacher, and Arrow etc as it is (theoretically) a shared experience now, but comicbooks...? No. A niche. A dying feeble medium. Television and film is where it is at now, and with the incredible effects and filming techniques now available watching these shows takes the comicbook and does what was never possible - brings it to a convincing and thrilling life.
Mass audience Live-action comicbooks have finally arrived. So why bother with paper and ink?
Since the COIE never really happened, why not set it up to happen right here and now, and this time, have DC stick to ther guns and have just a single Universe and timeline moving forward?