Just dipping my toe in here, so not wanting to be involved in an argument with the board. Quoting this only as an example I see often.
His own lawyer has publicly stated that the NCAA has no power to force Wisconsin to do anything. They could punish Wisconsin for not following portal guidelines, but they can't force Wisconsin to put him in. Have no authority to do so. The NCAA is a governing body on behalf of the institutions and has no power to force action from them.
The school is violating NCAA policy by not putting him in, but that's only punishment after an investigation.
Wisconsin saying he has a contract with them does not supersede the NCAA policy. Just like if he is placed in the portal does that change any potential contract with Wisconsin that he has.
The best course of action for him is either to file an injunction with the court to force Wisconsin to place in portal. Or to simply enroll at another school and play chicken with the NCAA over eligibility (which they would lose based on quite a bit of precedent).
If Lucas wants to come to Miami (and I assume he does), he should simply enroll and give everyone a middle finger.
(I'm not an attorney, nor do I play one on tv. Any advice here is purely for entertainment purposes and should be treated as such)