Senior Software Engineers taking entry level positions

I have a lot of questions and it might depend on the definitions of "senior" and "entry level" at the companies in question. I worked at Meta for a very long time and they wouldn't do that at all, and most other FAANGs I have close friends at wouldn't either. They want to evaluate you at the appropriate level based on your experience and if you don't meet the bar for that level, they will reject you instead of down level or consider you for a lower position. If you are borderline, they will round down to the lower level. So I could see it being likely that someone with experience taking an entry level role was judged to have not have enough experience for the mid level bucket. For example, at Google, people four years of experience are "entry level" (L3)