Eric Pankowski was released from his head creative position because of the way he dealt with others, according to PWInsider.com.
Pankowski reportedly brought a Hollywood mindset to WWE and was not willing to adapt it to a professional wrestling world. During his year on the creative team he got into several arguments with wrestlers over what would and wouldn't work on WWE television. Pankowski was not willing to listen to other ideas which turned many of his colleagues off from working with him and ultimately lead to him being removed.
Those backstage in WWE are not surprised he was released but are surprised the change was made this close to WrestleMania.