This is apparently the canon map of what the Splatoon world looks like (this was extracted from the interior of the Splatsville Ammo Knights).
As we can see, the geography is not the same as it was in the time of humans. Lots of things have happened.
South America is dislocated east relative to North America, which has rotated. That alone provides plenty evidence for plate movement
The North Atlantic is narrower than it is now. In the near future, the Atlantic is expected to continue widening, but after ~100 million years, it might run out of steam and start narrowing again
Africa has moved north and collided with Eurasia. This is going to happen in the future, based on the current movement of the African Plate. The Mediterranean has like 5 million years left
For that matter, Europe is once again a series of islands. That’s what Europe was like for most of the Mesozoic, and that very easily could happen again
Apparently, most of the continents have moved away from the poles, and are now coalescing around the equator
Antarctica isn’t here, but given its isolation at the south pole this may not necessarily be that big of a surprise on a map like this
Something happened to Australia and the assortment of islands in that area. Which is surprising honestly; the interior of Australia is pretty geologically stable, and since Australia is rapidly moving north as we speak, even after a short period of time it might not be in the same spot
Unless… and this is me getting speculative: maybe that is Antarctica. It could look like that under all the ice, and it’s bound to start moving northward eventually. It could theoretically end up near where Australia is now. Note how eastern Siberia seems much larger than it is in real life? What if that’s Australia? There’s no telling where Australia will stop moving northward
Coastlines are all different, which would be expected given long periods of sea level rise and continental drift
This reminds me of paleocartographer Christopher Scotese’s predictions for the future geography of Earth. Here’s an animation. Here’s a similar one. It’s not as close of a match as the Pangaea Ultima in Pikmin 3 is, but still pretty cool.
If I were to date Splatoon based solely on this map, I could give two dates based on how you want to interpret this. Taking it at face value, and interpreting the Atlantic as not having widened much, we might be looking at 20-50 million years in the future. But if you decide to go with the more speculative positionings of Australia and Antarctica, considering the locations of the Americas and interpreting the Atlantic as narrowing (like I personally will), I would give an estimate of 120-175 million years in the future.
