Zhulin has proven that he is a good coach, including for I/K.
Morozov would be the wrong coach for them at this stage, I am almost sure. Maybe in five years, when they have solved all technical issues and need some packaging, he might do. But now? Morozov has NEVER improved his ice dance students' technique.
Zhulin has done wonders with both P/B and I/K. The fact that these skaters sometimes make mistakes doesn't change that.