Accountability takes many forms. If he's using his personal account to post drivel from Disney's PR shack, he should expect a response, good or bad, to said drivel. The response may include associating the drivel that he has not personally or professionally distanced himself from within the confines of his social media presence with him and his name. He's created a reputation for himself by not distinguishing himself from what the PR shack produces. One of the consequences of this needlessly ingratiating social media strategy is that people on a forum might not hold him in the highest respect, if the quality of the work under his direction is not adequate to earn such respect.
If that's offensive to you, feel free to ring him up in your spare time and suggest that he get the PR shack to build their own Instagram accounts. Zach's not sacred, by far.