It's actually an HR(human resources) term. There's a standard document employees sign called a "separation agreement." See:

https://gusto.com/blog/people-management/employee-separation...

Companies go out of their way to use words that they hope will soften what is actually happening.

Separated almost sounds as if this was consensual.

That being said, Airbnb gets some credit for a decent severance.

Sounds like a weird new euphemism for laid off, designed to make it seem less negative.