But do we even know if that suit is going to be retconned as Superman's only ever suit? Or is it going to be the case that Clark just puts on a new suit? The scenes we see of him in the new suit aren't actually pulled from old stores. The two scenes that are, the wedding scene and Jon's birth, basically look exactly the same as they did when first published.
And yes, New 52 Lois says that she and Clark are their Pre-Flashpoint selves, but that's been pretty much in the cards for all of the DCU characters since Rebirth. Rebirth gave us the explanation that the only reason everyone is different is because some being stole 10 years off their lives. In other words: New 52 character + 10 stolen years = Pre-Flashpoint characters. My guess is that Lana's dream symbolized Nuperman and NuLois leaving the time stream, as it were, and then regaining their Pre-Flashpoint lives on "the other side" and then being deposited back into the time stream, wit things playing out the same way with the Lois and Clark mini and Tomasi's Superman and everything.
Reborn, I think, will be more about everyone else who is not Clark, Lois, and Jon remembering Superman status quo and history as it was Pre-Flashpoint, but those three might still remember their time as "time refugees." I mean, don't you think it'd be a bit of a cop out for DC to play up just how different this Superman is from the rest of the characters (as they are in the Post-FP timeline) and tease how his memories go all the way back to the Silver Age and also tease how he has something to do with the larger Rebirth storyline only to have them say "never mind, he's completely acclimated to this timeline now" in an a self-contained arc with Mxy, who doesn't seem at all concerned with any of the Rebirth stuff?
The problem with this, though, is that the larger Rebirth mystery kind of depends on Superman being an "outsider" for now at least. He presents the example of a character who regained his Pre-Flashpoint life after "escaping" the New 52. Plus, it wouldn't make sense for him to report the events of Superman Reborn to Bruce and Diana if the events therein change history to make it so he was never an outsider.The issue of Action that we're talking about has Superman remembering his life up till this point (including Jon's birth). It seems pretty darn obvious that this issue is there to establish what the working continuity is after Reborn, and I'd imagine that includes an altered explanation for Jon's birth, why Lex is a Superman, and why the Kents moved for a time.
My guess is that he'll be the only one to have some memories of what happened before the changes. I'm theorizing that he and Mxy will strike a deal, and Mxy will leave him memories so he can figure out how to combat Oz.
If such a retcon can be accepted then I don't see why Jon's birth and Superman's life being integrated into current continuity can't be accepted. I mean, if you're somehow worried that his pre-flashpoint history will be lost then I think you're safe. I like pre-52 is going to be the lion's share (if not outright complete) of the continuity for Superman going forward.