I listened to all the analysts on Bubblevision today and all I got for the reason why Chapeck was fired was that he wasn't good with the snowflake creators of content. Also that he put a lipstick on a pig of that disastrous earnings report.
The problems with Disney were created by Iger -- mainly his overpaying of Fox assets and further collapse of ESPN. I think he also underestimated the capital required to keep up with the Netflix content wars.
The real problem is that the effective margins of going from a bloated cable business to a direct to consumer model can not be fixed easily. I think at the peak every cable subscriber was paying $15-$20 for the ESPN channels regardless of whether they viewed it or not. Well that gravy train is over. No one under 40 even subscribes to the thieves running cable anymore. The only way to make those margins is to go to a PPV model like boxing or UFC.