Think about it for a second. When Barry committed this act of going back in time, (an act which I think was selfish and irresponsible) It created the Flashpoint time line, in which Wally was powerless and eventually murdered by Captain (at that time Citzen) Cold. When he finally "fixed" the timeline it wiped him from existence. Now was his death in Flashpoint that led to his absence in the New 52? Either way Barry is ultimately responsible for the current non existence of his nephew, on of the people who loved him the most. Do you think that Barry will be able to forgive himself if he ever remembers Wally. With these connections made, given his history with Wally, this is something serious to think about.
Did Barry Kill Wally?
Just because Wally hasn't appeared yet doesn't mean he was wiped from existence in this universe, he just hasn't made an appearance yet. For all we know he could be going to college in Keystone or something like that. He WILL appear just give it some more time.
@hunterscarlet: If you'll remember, Barry was about to fix everything and then "something" interfered, resulting in the revamp. The "something" was this Pandora character we know nothing about. So it wasn't really Barry who wiped out Wally from existence, even though in any just universe Wally would be the Flash over stale toast Barry.
This edit will also create new pages on Comic Vine for:Beware, you are proposing to add brand new pages to the wiki along with your edits. Make sure this is what you intended. This will likely increase the time it takes for your changes to go live.