Maybe Musk should have done that review before firing all of those FAA employees last month. Maybe those jobs were important.
What I wrote stands though, the article seems poorly sourced and incorrect about its interpretation of the tweet.
It's been reported that 400 new hires on probationary status were let go. None of them were involved in safety related operations. The FAA has around 45,000 total employees, so it's a rather tiny percentage, in any case.