Not true, but also not widely reported. Cops are fired all the time for a wide variety of reasons.
All of these officers will have new jobs lined up by the end of the week.
It's not on the unions, it's on the people who hired the officers.
This model you have inside your head, where there are public officials responsible for hiring that can exercise whatever they imagine are the prerogatives of the public at large when making hiring decisions, is fictional. Public sector unions, for better or worse, have long since obviated such jeopardy and effectively call all shots with regard to who is hired for what.