Pika would be an odd choice of main diet for a large hominin. They are small, are very able to move quickly and hide very well beneath scree and rock boils. The haystacks might work as food, but sasquatch could just go downslope, instead. Marmots are everwhere and probably much easier to catch, as would be wapiti, for that matter. The energy expenditure just doesn’t seem like a good trade-off.

Pikas live under big rocks in talus slopes. Their calls are as good as the prairie dogs’ in warning of danger.
And their population was not visibly that large. I would estimate less than 3 families per acre.

So pikas did not impress me as a primary food source, but downslope were ground squirrels that were plentiful in the summer months.

Warming is endangering the pikas…because sasquatch are taking advantage of it to go after them more frequently.

OK, maybe not so amusing, but grimly ironic would work.

Of course, there are many mammals that have been under protected status in the USA. This, however, is specifically regarding the reason for why the petitioning party feels the need is there (which is not the focus of this posting) for placing the pika under the protection of the Endangered Species Act.