It only matters because Will was over that same evening, so if it's the afternoon of the meeting day, he hasn't talked to Will yet, but if it's the next day, he has already talked to Will.
also, Sweeney told her about the speakeasy key when the raid issue came up, so her reply was half just Maggie feeling out whether there was a concern she should discuss with him, without actually informing Shaw that Sweeney has the key and she knows it
(tbh Maggie finds the warden locked posts every time Shaw thinks she might have fucked up a little dismissive of inmates, like Shaw feels like it's only important to be accountable to fellow wardens, and the other half of the ship doesn't matter, even if they were affected by her actions.)
(yet another thing i find very funny about her in canon: she falls deep into existential confusion and is doubting the nature of her own reality basically all the time, and when someone tries to meet her where she's at and make her feel better by going deep into "what is reality anyway, are any of us actually real, mannnnnn" she just gets annoyed about it)
(this contrasts with misty, who is well aware that maggie doesn't like her much and is bothered by it because she still kind of wants to have a crime movie marathon with her)
also Maggie is a meticulous planner, which is probably why Shaw gives her headaches. "How can someone who claims not to have emotional responses be so much more impulsive than me? Why? I'm all emotion, but at least I think before I act."
(she'll do things that don't make sense to her if she trusts the person telling her to do them enough, and she'll do things on the orders of people she doesn't trust if the things they're telling her to do make sense to her)
relevant bit of meta i wrote for another app