Does it, though? "Champ" is also just another word for "chomp" or "bite." So while there may be a play on words here beyond just the rhyming, it's possibly nothing more than something comparable to "Drew's Chews."
At any rate, we see several bags of Stamp's Champs on the Rasberry dinner table and don't see another dog on a bag until the ending shenanigans.
First off, is that the only other place we see these chips? I think that's important.
Also, I didn't know about that pun. Huh.
I dunno, if this is a "spot the difference" to determine an AU, its not very clear. The trope is meant to be utilized in a more straightforward and less ambiguous way. The dog having a different rank and being on a chip brand that only appears in one other scene doesn't offer a significant, clear tell like, the Coca Cola brand symbol saying "Pepsi" and Pepsi's disc saying "Coca-Cola."
I don't have an answer for that, nor am I saying -- let me stress this -- that it sounds like a good idea. It just appears to be what we're getting stuck with, either in the form of this universe's history transitioning into something else or an additional new branching timeline off of the one we started with here.
For that matter, one doesn't even need an AU to explain Zack's survival. FFVIIR is already an AU relative to the original game.
I don't see how it could be used at all. If they introduce an AU, that means you use it, right? What would be the point of introducing the concept and not using it, save for showcasing a single scene of Zack living? It makes no sense.
If they do use it, then that means we either visit it, or we're gonna be in it. That seems like a lot of work from a game design and story scenario perspective that's bizarre. I just don't see how it threads that way. Zack showing up can easily be a nod to the past and such, without it spinoffing that hard.
The FFVII-R Ultimania will be very interesting to see. Because I'm sure they'll talk about the ending in detail.
An AU of an AU?
Probably not what most of us were hankering for, but we'll see what it means.
I still think this is more akin to a time loop but we'll see
A loop would make sense and fit with what they've done before like Dissidia. And it also doesn't nullify the OG. It gives the Remake space to be FFVII while also teasing differences that ultimately lead to the same end.
Ironically, I didn't have too big a problem with this changing-the-past stuff until I verified the two Stamps, as it led me to the very realization you've pointed out. XD
My problem is how it's superfluous. An "AU-of-an-AU" as you put it. It's an entanglement that's unnecessary because that's not even Zack. That's Zack-2. So why even do that if it's only meant to do that?
If the next game is gonna use AUs, then it's gonna have to go all the way and that's gonna be insane. That's a Chekhov's Gun that'll explode. I can't even fathom how that would work. From a game design perspective as well.