Is the phrase "they don't know how to comb his beard" (referring to Allah) and the person laughing at it considered apostasy that expels one from the fold of Islam?

There is nothing in uttering that phrase that makes it an act of disbelief (kufr) expelling one from the religion, unless the speaker intended to mock the practice of growing a beard. As for merely mocking a person, this is a sin and not an act of disbelief. And the listener's laughter upon hearing it is not an act of disbelief, as long as they did not intend to mock the practice of the beard.