Depends on the intent. I don't know Flexport's situation, so I can't say this is what happened. But, it's pretty common to parachute in outsiders to do the terrible things you want to do (layoffs, big policy changes, etc) that you know will have an adverse effect on morale. Then, once it's done, you boot the outsiders and commiserate with the masses..."yeah, sorry, clearly that was a bad idea".
I’ve worked for one at Cruise who got “parachuted” like you put it and he was generally well respected as he definitely cleaned up the house there as the company scaled massively - I’d consider working for him again. That is to say it works for some companies but probably not everyone and ymmv depending on who you parachute.
I guess it depends on whether the company owners want to parachute someone in who has outside expertise/experience and can help out, or just someone who's a fall guy.
I think this is kind of a silly thing to say. It's a high risk path to bring in senior leadership - it means you don't have anyone internal you think is good. So it's not surprising when the move fails, whether that external hire was from amazon or anywhere else.