really
i thought it meant what is pizza
That doesn't make any sense.
If you don't already know what a pizza is, then how do you know to shorten the phrase down to three letters? Even knowing that wip means "what is pizza" implies you already
know what pizza is, meaning you never even had to use that phrase in the first place! It's a question you never have to ask again after getting the answer, making the whole idea of needing to shorten how you ask that particular question an entirely moot point.
wip is obviously supposed to mean when is pizza. That's a question everyone asks often enough that you pretty much have to shorten it to three letters. Or else the pizza is already going to be there before you even finish asking the question.