So who or what is this Jack reference about? Is this some other (no not again!)hypertime version of Wally?
Hope not… things are complicated enough as it is. However, perception is built into the Hypertime concept – i.e. you can find yourself remembering an alternate timeline that you didn’t live (this would explain things like finding your shoes next to the couch when you’re absolutely certain you left them under the bed – one of your hypertime duplicates did in an alternate timeline, but you remember it anyway). Since Wally’s crossed zillions of possible timelines, it’s easy for his memory to have picked up bits from another one, just as in the past his eyes have appeared blue (like Walter’s) in other series.
Somehow, I have this feeling that they won’t be willing to keep it that simple.