Considering that every other flight told Plague that unannounced challenges should be the norm and that we overreacted when it happened, I think it's fair if we challenge without giving any heads up; we'd simply be playing the game as it's expected from the rest of the playerbase.

That being said, the Light Sprite is a certain way to lock in both weeks as a win; even if another flight wanted to challenge, no amount of fanfare would win OOF support away from potentially winning the sprite. Plague's bank is hurting too hard from fighting Water to get even close to offering a prize equal to it, and I don't imagine other flights are willing either.