What is the ruling on mocking someone by calling him "the awaited Mahdi" as an allusion to his lateness or absence, and is that considered disbelief?

It is not permissible to mock a Muslim, as Allah Almighty has forbidden it in His saying: "O you who have believed, let not a people ridicule [another] people; perhaps they may be better than them; nor let women ridicule [other] women; perhaps they may be better than them. And do not insult one another and do not call each other by [offensive] nicknames. Wretched is the name of disobedience after [one's] faith. And whoever does not repent - then it is those who are the wrongdoers." If the mockery is directed at the Mahdi, who is a righteous man from the progeny of the Prophet (peace be upon him), then its prohibition is more severe, and its perpetrator should be given a harsh disciplinary punishment. However, this mockery does not amount to disbelief that expels one from the fold of Islam.