The media always liked McCain for various reasons. I understand he sat on committees involved in media regulation so the big media companies fawned over him for that alone.
The left leaning journalists liked him because he would attack fellow Republicans and now like him more than ever because of his visceral hatred of Donald Trump.
McCain’s hands are in the Trump “dossier”.
He was probably a covert leaking source to the enemedia for decades and thus the love. Their hatred for him in 2008 was just “business” and professional wrestling (as was his own “conservative” stance, “Grrrr! Imma Maverick!!!”)