Let me clarify: In modern history, it's virtually unheard of for an actor's name to appear on the cover of a capital-p Playbill for a Broadway show or a proper National Tour. (I don't care about what happens in summer stock.) The main exception being one-person shows or theatrical events (i.e. John Leguizamo), which is sort of akin to a possessory credit for an author on a Playbill cover.
What other recent Broadway musicals have had the star's name on multiple merch items (shirts, mugs, keychains, tote bag, etc)? Nathan and Matthew in The Producers? (Not concerned about plays with stars, since those are usually limited runs and they're not concerned about evergreen merch.)