The state of Utah has zero say as to what the FBI does and Cox knows he isnt' going to interfere with a federal investigation (which is a crime in and of itself).
This is all about the IOC trying to give itself an "out" (theoretically they could pull the games) and a political statement.
Technically SLC is the USOC bid city and the USOC would also have to agree to the contract, so this is more of an issue for the USOC than it is the SLC committee.
But in reality, no one else wants to host the 2034 olympics and as time passes no other city will be in a position to become the host city if the IOC wanted to exercise its option and move the olympics.
Neither Cox, Utah, nor the SLC committee will do anything. And when they don't, the IOC won't exercise its right to move.
Its all a ridiculous but meaningless political move/statement by the IOC