Yeah, especially cats. Even people who dislike the overrepresentation of mammals in the game are ok with Ocelot, Serval etc...
Antelopes (hoofstock in general) are important for the game because they are charismatic and irl zoos have dozens of species of them. I think cats, antelopes and IMO dogs are all fine to add more of. But,
an animal that is super charismatic, warm-blooded and underrepresented?
Birds... Even the bigger (i.e. doable) species like cranes and rhea and swans would add to better representation of birds.
And finally, what we really need more of is insects and the like. We need maybe dozens more!
At the end of the day, PZ should be somewhat reasonable cross section of the real life diversity in zoos.