Sure, but an ex-FAANGer probably has a better shot at actually getting hired at another FAANG (when the job market improves) than someone who's only worked at no-name shops or local governments.
The implied logic behind that is "I know my company is a worse option than many of the other ones out there, so I'm going to only hire people who those other companies would not do business with." It's inherently a low self-esteem attitude.
People leave, sometimes suddenly and without warning. The high self-esteem way to deal with it is to do your best to provide an attractive working environment, accept that some people will leave, and try to learn from each departure. That way you have the option of profiting from the talented employee who totally could make more at a FAANG but happens to like your company because you provide good management, a worthwhile purpose, or the actual ability to write code rather than deal with company politics.
Reminds me of this chestnut: "We don't train our people! What if we do, and they leave?"
"What if you don't, and they stay?"
Heck, having someone sharp with a new perspective even for a year could significantly improve things for the better. If you get out of their way of course.
