In these cases where they have to rehire someone, does the employee usually stay after? Wouldn't the workplace be kinda hostile now with the manager who fired you?

Unlikely it was the person's direct manager who made the call to fire them. I would normally assume this person won't be up for a promotion for a long time. And they'd need to do everything by the book going forward.

On the other hand they've shown everyone they have backbone and that Atlassian ss petty and engages in illegal retaliation. So the company may be forced to be on its best behavior with this person in the future.

Yeah I can't imagine that playing out particularly well. Maybe at a company as large as Atlassian it is feasible enough to stay isolated. But I'd think the relationship is tainted from both sides at this point and doesn't favor either party.

I don't know about other companies, but I don't really interact with my manager outside of 1 on 1s like once a quarter. Also, it's never his choice to fire someone, it's always from above. I'm sure if he was forced to lay someone off he'd be just as happy as they are to have them back.