That's quite the difference than what was being mentioned earlier that we would have virtually no room for mods. Anyone who can have over a hundred plus mods with no compatibly/ performance issues deserves some praise. Some may mention that real zoos have thousands of species but the average zoo build never exceeds 400-500 total animals due to performance limitations. Sure the choice is wonderful but why would anyone download a mod for an animal they don't intend to use
To voice my opinion on this topic though, I'm neutral about raising this limit because it is of no concern for the average player with a dozen or so mods in the near future
A lot of them are ones that are very similar to existing animals, so someone can go with the exact species they want while still having the base game ones.
One example is the American Wood Bison, it's one that would be of interest to different areas for people who live in different areas, or similar. Sure, you could go with the American Plains Bison for it, but that's for other things. or someone wants the American Black Bear. Simple mods with no real conflicts with existing ones.
A lot of people also don't like swapping mods out if they don't have to, so some animal might be a great thing for a specific zoo or zoos, but not several others.
There's also clusters of animals that have different purposes such as several farm animals that are extremely common for petting zoos and handling that is pretty much entirely via mods now.
Not everyone would get every mod, but there are several people who do like having them, and sometimes just finding that perfect animal for your zoo.
Then you have things like with ZSU and people who might try something similar with closer groups that might want more specific variety, or one from another zoo game...or just the animal they really want (With 2 basic deer species, I'd still love to see the Key Deer pop up, but I doubt it will happen since more spread is better for the game with official DLC, while Mods work great to fill in the gaps).
Which is contrasted by other work that people have done such as the massive amount of work on aquarium species which require a lot of different animals to actually work in a way to look right when designing areas for them.