Unfortunately for those being let go, having a FB stint on your resume is considered a red flag by most hiring managers, especially in the Bay Area. The longer the duration of that stint the harder it's going to be to find another job.
No matter what you say about the business, the people are fairly hard working and smart. More hard working than most other FANGs and it shows when they job search.
It may be a red flag for some, but IMO a FAANG/GAFAM/etc experience on a CV is one of the best parts of it, unless one can top even that one. Personally I dont like or use facebook much, but I respect their engineering at that scale.