I'm all about players being mature and disciplined and would usually feel annoyed about something like this but, you know what? Feck it. Mourinho was such an unusually toxic manager, I'm ok with players rubbing his nose in what happened.
He chose to turn this season into an unfair personal battle between him and the players. He was constantly belittling them, while they were not allowed to speak up for themselves. What goes around comes around. Prick.
While I agree, players should probably pretend to be the bigger men. And in that particular case, I'm not even sure about what that post was about, it could be a message related to Mourinho and that would be disappointing or it could be a simple promotion.