Does the Apple Form work?
Which form is it ?
Who holds the account under which the app was registered ? If it is the other person, he has ownership of the name. My further comments assume that the other owns the account.
You say you have EUIPO ownership. As EUIPO is for a transfer, does that mean the other person has signed such a transfer ?
AFAIK, Apple cannot force so to delete the app (unless they consider the app or account violated the appstore rules).
But in your case, you have a dispute. If I understand, that means that the other person has not signed the transfer agreement. If so, Apple will probably do nothing.
Note that you cannot submit the same app under a new name ; it would be rejected as spam.
So you have to terminate the dispute and have him effectively remove the app. That may require filing a suite and go to court.