Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Sheikh Abdullah Al-Mutlaq is known to be on the methodology of Ahl Al-Sunnah Wal-Jama'ah, in creed and in action (practice). He plays a significant role and has a considerable activity in the field of Dawah (calling to Allah), enjoining good and forbidding evil. It is sufficient a proof of his vast knowledge that he was chosen as a member of the committee of the greatest scholars. The fact that he is not well-known like other famous scholars does not undermine his status. And we are not aware of any opinion of his, which contradicts the belief of Ahl-Al-Sunnah.
It might be possible that those who disapprove of something about him have reserves regarding some of his opinion in the field of Ijtihad (an effort in trying to give the appropriate ruling on something based on analogy for which there is no text in the Qur'an, the Sunnah and the consensus of scholar). In such matters the scholar follows the evidences he thinks are preponderant. And it is not permissible to defame him regarding his Ijtihad even if another scholar is of an opinion different from the Sheikh's.
You have to know that we should have good manners in relation to the scholars, because insulting them is insulting the religion.
In this regard, we cite the saying of some of our righteous predecessors: "Backbiting scholars is poisonous and it is known how Allah humilates those who defame them."
Allah knows best.