This simply seems like an attempt to collect his $5 million (or whatever his salary for the 2023/2034 season) and nothing more.
Lawyers using the technicality that he never signed a letter of resignation which was specifically required by the agreement - and that he was permitted under the agreement to announce his "resignation" in other ways without actually technically resigning. Since he didn't sign a letter, he can now claim a breach or wrongful termination of some sort.
Some pure BS stuff, but it may work. Makes all parties look silly.
The real amateur lawyer in me, thinks if WVU had simply outright terminated him after the incident, for breaching whatever morality clauses were in his amended contract they would probably 100% be in the clear. There would be no grounds for any buyout or any settlement. But they tried to at least give some dignity to Huggins on the way out, and now it could bite them in the ass.