Cougars. Under the slim chance that we get a North America, I think that cougar would be easily passed over for Porcupine, Elk, Moose, and Coyote. I think that the only way I potentially see it, is if they release a 7 animal pack for North America, like with SE Asia. But I doubt it. The new Africa packs seems to indicate that they are going back 4+1. Sigh
Same with American Beaver and American Alligator. All three are really cool animals, that tend to get overlooked. My local zoo only has cougar and beaver because they have an entire native, "Cascadia", section.