Just as a note: In one of my cities I still had the Cauldron tutorial questline active, so there was no repeatable quest in that city (because normally such tutorial quests take the place of the repeatable quests). However, as soon as I finished all of the Cauldron quests, one of those old repeatable quests popped up. Only one, however; once I cleared that one, no other ones appeared.
So I guess something about the event starting accidentally queued a repeatable quest to pop up at the first available opportunity.