Is the present king of France bald? I'm not sure where Quirrell and Harry stand on the truth of vacuous statements- if Hogwarts plays zero games of quidditch, all of them do not involve the snitch.

Also, technically Harry wished that "in Hogwarts we should play quidditch without the Snitch." Should can mean "will" but it can also mean Quirrell will somehow make it a moral fact that quidditch should be played that way, not a factual matter of actually playing that way.