Yes, many of us sense the Orang Pendek is an evolved form of Homo floresiensis. Additionally, the fossil candidate for Yeti probably is a form of Dryopithecus, maybe Gigantopithecus. Sasquatch/Bigfoot are probably Paranthropus. There are some in the Bigfoot camp that think Sasquatch are Gigantopithecus, however. Time will tell with the discovery of these species.

In my book, The Field Guide to Bigfoot and Other Mystery Primates (NY: Anomalist Books, 1999, rev. ed. 2006, with Patrick Huyghe), the entire notion of separate species and genus worldwide is explored.

But with the Yeti and the Sasquatch, in my opinion, the situation is a little bit different. You see, these 2 cryptids are so similar to each other that, in my opinion, they must be members of the same species (or at least the same genus).
And they also happen to be so unlike any primates from the fossil record, that I just can’t identify a good candidate for either one of them. Therefore, it is my hypothesis that the Yeti and the Sasquatch are creatures which are completely new to science. So new, in fact, that the fossils of their ancestors probably haven’t even been discovered yet.

This proves a very important point; when you’re dealing with hominology, you cannot just lump them all together, and then proclaim that your own pet hypothesis must explain them all. That’s just not how it works at all.
Indeed, I shall once again repeat that, in my opinion, the Orang-Pendek is not closely related to the Yeti and Sasquatch at all, and that it is most-likely descended from its own, and very uniquely-evolved, ancient lineage.

Or wait… maybe I do.