You need someone with some personality on a show like that to make it somewhat entertaining for anyone that's interested in watching. That's why AJ is there again.
Along with that comes some hot takes, or a personality that may rub some people the wrong way, or from the sound of it, some obnoxiousness from the guy that had that role before.
Despite it being a shitty move to fire someone before the holidays, that guy isn't doing himself any favors by letting all future employers know how he'll handle things publicly if they have to let him go too.