Don’t you already share the world with numerous intelligent species? Elephants seem to run on intellect as much as instinct, and adapt their environments around them. Octopodes and squid can be pretty smart. Cetaceans have big brains, and use complex sounds to communicate. I think beavers were mentioned upthread. Apes, monkeys, and even raccoons act a lot like little humans, with their grasping hands. Your species is not uniquely unique.
So long as mentally handicapped humans at the same level as humanzees count as humans for whatever purpose, your humanzees largely do as well. Other than straight genetic categorization. Probably. I didn’t vote at first, but I changed it to say, yes, they’re human. At least in part. But maybe I don’t understand the question.