Dolph shows up on the night of the tournament final to claim he deserves to be in the match since he never officially lost the title. It becomes a triple threat, Ziggler then wins the belt again in cheap fashion, stealing a pin or putting his feet on the ropes or something.
Next week, Ziggler AGAIN forfeits the US title, necessitating either another tournament or maybe a battle royale. Ziggler cheaply wins the title yet again and forfeits it once more, before any of the guys he's screwed over can get a proper one-on-match against him.
You can maybe even repeat this cycle once more (stealing the belt off the hook during a Mania US title ladder match?) before Ziggler's last challenge to regain the title ends with him getting his ass kicked by a face.
What better move for a "showoff" character than to brag that he can win a title whenever he wants, and then lose it "on his own terms" (when he's really just avoiding actual defenses like a coward). Between the cheap finishes and Dolph's obnoxious forfeit promos, this would actually be an original way of generating heat.