Wally said "It's getting harder to remember" (whilst holding his hands to his head, no less). Because of that line, we can no longer assume that Wally still remembers absolutely everything. Geoff Johns put that line of dialogue in there for a reason.
We know that he remembers being in a relationship with Linda.
Another thing we know is that all the flashbacks in the new Titans series have reflected "Titans Hunt" continuity, rather than the Silver Age depiction that was in continuity up until 2011.
It's speculation until it's printed, or at the very least until it's officially announced.