The humanzee is the theoretical hybrid of human and another primate. No such humanzee has ever been documented in the modern era, though genetics suggest in our distant evolutionary past primitive not-yet-humans ancestors have mated with chimps and humans mated with neanderthals in the past. In fact the soviets even made a half-hearted attempt of breeding humanzee with little luck.
Modern humanzee are rather unlikely to occur due to the different number of chromosomes between modern humans and all other primates making a viable hybridization rather unlikely. However, hybrids between closely related species with different chromosomes have been recorded on occasions, though usually it's rare that a mating will lead to a viable one even between species that can produce such hybrids. Considering how rarely humans are sleeping around with modern apes, how rare a viable hybrid would be, and the difficulty of documenting the occurrence of one even if it did exist (who would admit to it!?) it is at least theoretically possible, if extremely unlikely, that a human ape hybrid is possible, despite our having not yet documented the existence of one.
So lets theorize that this a hybrid between human and either chimp or bonobo occurred and was documented, with scientists using DNA tests to confirm it is real and not a hoax. No I don't want to think about how this happened, lets skip over the how. You can presume unscrupulous scientist research, strange ape found in the wild being tested as a hybrid, or maybe bestiality was legalized in Las Vegas and someone had an odd fetish; the specifics of how aren't relevant to this question and I really don't want to distract it with going into that part. However it occurred it is not due to genetic engineering or scientists making something impossible happen, such a hybrid is possible, if extremely unlikely, without scientist intervention.
Regardless of how it is confirmed that it occurred. Lets say any such hybrid is extremely unlikely to occur and is also sterile (both very likely considering the genetics). How would society respond to the revelation that such a hybrid could occur, even if very unlikely. Would society redefine apes in general with this realization? Would there be any religious implications to this discovery? Would it have any effect on how man views them selves as separate from animals? Would science/biology/medicine be changed by the realization that a hybrid can occur?
edit: I realize that it's hard to answer this question without knowing what the humanzee was like, which is an entire world building question in it's own right. Thus I'm going to go with a situation where even the people of the world don't know much about what the humanzee was like. Lets say for the sake of this question that the humanzee did not seem to have human level of intellect, but that it died, but not due to any side effects of being a hybrid, before we could discover it's exact intellectual capabilities.
Physically it looks like a cross between human and ape. Some people think it looked cute, some think it hits the uncanny valley hard and thus is ugly; so people can't decide rather or not the like the features of it.
There are many unanswered questions yet about what the humanzee was capable of. Considering how hard it is for a hybrid to be produced, and the obvious ethical concerns with trying, it's unlikely were going to have any new hybrids to experiment on to answer these questions for quite awhile.