But there is a threshold where it stops being a test of foundational knowledge and starts being a test of arbitrary trivia, and favors who has the most free time to study and memorize said trivia.
But I agree, a lot of MLE roles don't get asked such things.
I think the OP's guide is closer to interviews I've seen for phd programs.
They explicitly say something harder than eigenvectors in the GP.
I was imagining something involving the spectral theorem or something like that, ie. beyond the most basic linear algebra.
OPs guide seems to cover plenty of things I'd expect someone to learn in undergrad, I think I touched on almost all of this - except for stuff involving jax and recent CNN architectures, both of which can easily be supplemented online.