What does Title IX have to do with anything?
Basically Urban Meyer's wife knew his assistant had hit his wife, it's not known if she had told Meyer. He has admitted that he knew the assistant had a prior allegation where he pushed a woman into a wall. Title IX has nothing to do with that.
Nor did Meyer violate any laws as the whole thing had been investigated by the police, and charges were not pressed.
If Ohio St. determines that it's a violation of Meyer's contract, they can let him go. But Meyer has nothing to fear from Title IX or the law, as he didn't violate either.
Football: Urban Meyer faces questions over Zach Smith at 2018 Big Ten Media Days
The pertinent clause that would allow them to fire him for cause:
New contract provisions could pose problem as Ohio State's Urban Meyer is placed on leave
Is for Title IX violations, something that an incident between an assistant and his then wife does not fall under.
Ohio State can (and probably should) fire him, but they won't be able to do "with cause" and will have to buy out the contract. I suspect that Ohio St. is already in talks with Meyer to make him quietly go away.