The Singularity is where the fight with Sephiroth and the Whispers takes place, everything else outside of it should have occurred at a fixed moment in time. You think the Singularity changes the fact that Zack’s last stand was in September and Cloud left Midgar in December?
A singularity point is a location in space-time that connects to all points in time, meaning that while Cloud and the others were fighting Sephiroth, Zack's last stand occured. They are temporally connected. No, it doesn't change the months each event occurred, but it allows simultaneous events like the Whispers exploding to occur in the past and present. That's literally the point of a singularity.
Again, that’s specifically where Cloud and the gang fight the Whispers. Then they leave and continue on in whatever new world they’re in.
They leave and find themselves at the exact same spot Zack and Cloud in Crisis Core are in, 3 months in the past. That's why they pass by each other because they are in the exact same spot, just at different times. The singularity point allowed us to see how these two events unfolded concurrently.
Symbolism? I dunno why that idea is such a stretch considering how much of it is used in this series
But it's
not just symbolism because the Ultimania itself addressed it from a completely diegetic perspective. They didn't just dismiss it as symbolism. In fact, they specifically treated it as something
more than symbolism and brought attention to it as a key narrative point of mystery.
Because the Whispers transcend time, them being defeated in the present affects what they were able to do in the past. That’s literally why Zack is alive in the first place.
Their transcendence of time is not a dismissive hand-wave for phenomenon. We see what they do, and what they did. Their destruction was witnessed and felt by Zack in Crisis Core, and Cloud's group in FFVII. This is not a mystery. Their blow up happened before our eyes and we see the same golden light and sparkles fall on Zack in Crisis Core while it also falls on the present Midgar in FVII. This is a simultaneous occurrence. You saying, "but what if it isn't?" isn't a point or theory. That which can be asserted without evidence, can be dismissed without evidence. And you're not providing any evidence to support this not being a simultaneous occurrence as the game/text presents it to us.
Dude, the story isn’t even over. Not a single one of us here is in any position to be as sure as you are of what the hell is going on lmao the most we can offer here are ideas.
That literally doesn't matter. Cloud could turn into a brain eating zombie in Part 2, and no one would see it coming. Because it's pretty obvious nothing in the setting or narrative alludes to such a freak occurrence happening. We as the audience can follow the evidence, and what is clearly being alluded to through the narrative and setting, especially thanks to the commentary/clues provided by the book materials themselves. Just because the story isn't over doesn't mean we have to abandon critical thinking or stating what's obvious to our eyes. And certainly still have to support what we're gonna claim is going on.
You already accepted the Singularity as being a place transcending time, what else do you need?
I never accepted the Whispers somehow eating time like Langoliers or something. I believe the same laws of time currently exist, even with time travel shenanigans. And the temporal plot holes that exist need filling if you're going to posit a single timeline as the explanation for the time travel scenario.
Beagle represents the world before the Singularity event, terrier represents the world after. It’s really not that different than using the two to represent separate parallel timelines, it’s just a matter of whether one can go back and forth between the two.
We don't see the Terrier Stamp mascot representing the world
after the battle with Sephiroth in the singularity. We only see it representing Zack's world during the Crisis Core time period, 3 months in the past. We have no evidence at all that the Terrier Stamp exists in FFVII-R's current reality inhabited by Cloud and the others. But we
do still see Beagle Stamp in Intergrade. And let's not forget, we have commentary from Nomura himself stating that Yuffie is going to meet up with Cloud and the others in Part 2, picking up from Intergrade's ending. So why would Cloud and the others be in the Terrier Stamp universe?
We see the terrier with Zack after the Singularity event has changed the past. We don’t see it with Cloud yet because we’re still in a pre-Singularity world during most of FF7R and similarly during Intermission. Once we leave the Singularity, then we see if Stamp matches with what Cloud remembers Stamp looking like. If he keeps his memories of a pre-Singularity world, he’ll remember Stamp as being a beagle. But everybody who was outside of the Singularity remembers him being a terrier because to them, he always was a terrier.
Obviously, that’s all just guessing. But if you’re familiar with stuff like Steins;Gate, it’s really not such a stretch.
I'm familiar but we don't see that currently at work at all. Going by what we
do see after the final battle with Sephiroth in the singularity, we see that both parties continuing on from the events shown in FFVII-R's ending. Cloud and the others are heading to Kalm, and Zack is going through Midgar to visit Aerith at Church. No evidence is provided during these events that show Zack's timeframe suddenly changing from
Crisis Core's, to
FFVII's. We simply see these events continuing on from their previous introduction from the ending.
Unless something's shown or explained that says otherwise, it is a massive leap based on no evidence other than the desire to make the two characters be in the same timeline writ large. It's working backwards from a conclusion, and trying to make the evidence align with it.
About the Stamps in the Yuffie chapters, do we see both old and new, or only the old one? I’m trying to have a go at this clusterfuck but I can’t watch this before several hours so 
