There were more than 2 lakes but the specy is almost extinct so these areas are where you can still find some.

Well it's native to the Xochimilco "lake system". Sometimes its hard to say what's a different lake or not but it's the same system of lakes. They also used to be in Lake Chalco which at certain times of the year could connect into the same lake as Xochimilco. Regardless, it's always been a tiny range

My understanding is they were in other mountainous areas as well in central Mexico but their habitat was much more reduced there so they went extinct even faster.

one example: https://www.researchgate.net/publication/382147531_Chronicle...

This paper is about the closely related Ambystoma velasci. The axolotl is Ambystoma mexicanum.

They are closely related enough that there's some evidence of hybridization but they are separate species. A. velasci is not endangered.

A. Velasci is definitely endangered in its natural habitats and it was also called Axolotl in nahuatl.

I don't think it is interesting to argue if there is one axolotl that is more important than the others, even if the one from Xochimilco has the particularity of staying in its larval state.

Ambystoma velasci is actually classified as "Least Concern" by the IUCN

https://www.iucnredlist.org/species/62130287/53974804

I'm not arguing one is more important than the other but only one of them is critically endangered and only one of them is a powerful cultural indigenous symbol.

Ambystoma velasci is also an "actual" salamander. The unique thing about the axolotl is that it never goes to the stage where it leaves the water. It is the only salamander species known to do this.