Is a brother entitled to marry a religiously uncommitted girl despite his parents' rejection and their threat to sever ties with him and disinherit him?

You must dissuade your brother from marrying a woman who is not committed [to religious principles], because the Messenger, peace and blessings of Allah be upon him, commanded marrying a woman of religious devotion. This woman is disobedient, drinks alcohol, and does not observe proper hijab. Disobeying one's parents is a grave sin, and the family's rejection of this marriage is Islamically valid because it is an enjoining of good and a forbidding of evil. It is permissible, rather, it is advisable, to shun your brother if shunning him will deter him and distance him from this marriage, for his marriage to this woman will distance him from his religion. As for disinheritance, it is only permissible if he apostatizes from the religion, and it is not permissible to disinherit him as long as he remains within the fold of Islam.