Probably depends. Theres a big change the vacuum ( if properly aplied, which probably hasent happened lol ) will keep em sticked to the wall and the inevitable collapse of this backsplash willhappen when that vacuum fails completly unexpectedly because of too agressive breathing near the tiles.

Indeed, itll stay on . Untill your steam from cooking takes them off and your backsplash takes a swim in your dinner...order food in and redo it then, will be a good story on birthdays

Are you flipping the house? Leave it on, if you hope for them to stay on longer than spaghetti cooking time, follow the average advice on here