Hill put Larry up to the whole: cancelling the rivalry fiasco. Larry used it as leverage to get a better contract.

Larry was given a contract extension in April of 2015. Just a little of year later (after getting destroyed by Gonzaga in the NCAA tournament) he was given a boost to his contract of just under a million. This happened in Nov 2016.
Larry cancels rivalry next month in Dec 2016

Boylen comes on the radio and says that Chris Hill tried to get Jim to do the same thing when Utah went to the PAC12.

Chris Hill tried to do it in football.

Larry knew it was total PR suicide to do what he did and he wanted to get paid for it.