>>10003676punk started it. punk did a live panel or Q&A a few years ago and said he hopes Bischoff dies. the moderator or host tried to walk it back but Punk doubled down on it.
there's also the stupid and ageist comment here, see pic
and no, they've never dealt with each other so punk is just talking shit on someone he'd figured is unpopular enough so he'd get away with it.