Does the Poe story, "The Masque of the Red Death" touch on the evils of "elitism" and "snobbery"?

Not directly. Prince Prospero only invites his rich, high cl friends to stay with him while he hides from the Red Death, but the story doesn't necessarily touch on the 'evils' of that. What you have is a group of well behaved rich people enjoying a friend's lavish home. If the story talked of how the rich could hear the cries of the poor who were outside dying, then yes it would speak of elitism and snobbery, but since that is not the case those topics must be inferred. The ending does show that death finds everyone, not just the poor.