Feige had to answer to Perlmutter at that time. Perlmutter was the big boss then and could veto or change directions of the movies. Now Feige only answers to Bergmann and Chapek and he pretty much has carte blanche veto power.
You can disagree with it but it's undoubtedly different.
So magically he doesn't have to report to Chapek? Of course he does and Chapek could still veto things if he wanted to. Fact of the matter is Perlmutter had absolutely nothing to do with the Mandarin twist.
You can disagree with a fact if you want but Feige liked the Mandarin twist idea, just the same as he liked the Taskmaster twist idea.