The odds of a real Yeti are perhaps even higher, due to the long record of apes in Asia, and the odds for an Orang Pendek are much higher, especially given the existence of orangutans and (recently) Homo floresiensis nearby.

But you’re right; until it can be shown that there really is an ape that fits the description of Bigfoot, it makes no sense to ask if it migrated to North America 13,000 years ago, 50,000 years ago, or a million years ago.

The problem with that hypothesis is that it is ONLY a hypothesis; it is not supported by any evidence whatsoever. We have at least sightings of Bigfoot and Bigfoot-like creatures from all over the world, but that evidence only goes back a few centuries (in oral folklore) or a few millenia (if you want to count things like the story of Enkidu). There are obviously no surviving oral or literary records of such beings from Siberia 13000 years ago, and there are no known fossils of candidates from there, either. Gigantopithecus is poorly understood; it was a large, non-human primate, but whether it was bipedal is strictly guesswork, and its range is not known to have extended that far north.

This leaves us with no more evidence of a Sasquatch migration with the Clovis or Western Stemmed cultures than of Bigfoot arriving by flying saucer, as some would have it, or being a spirit of the forest with no permanent physical form.

At any rate, a lot of animals obviously did cross from America to Eurasia or from Eurasia to America, many of them long before any plausibly suggested first human migration. If you want a ray of hope, those are probably better analogues than Homo sapiens.

Regardless, it does show that there was another culture in America contemporary with the Clovis people. Unfortunately, the Western Stemmed projectile culture was already known; this just pushes back the earliest date at which they are known to have been here.

I think from a cryptozoological point of view, the article Hominins did not need boats to settle islands is more interesting.