The new Dell XPS's managed to squeeze their camera/mic up above without needing a notch[0]. I'm guessing Apple had the ability to do so too but decided not to either because a.) they're planning on adding FaceID at some point in new models and/or b.) because they're trying to "unify" the design aestethics on macOS and iOS
[0] https://m.media-amazon.com/images/I/81FV+91am5L._AC_SL1500_....