IMO, the notch was pre-emptively introduced to accommodate for when Apple does figure out how to fit FaceID within the top lid of the MacBook. They probably can make the bezels super thin all the way around while accommodating the camera as is right now, but they don't want to do that to then introduce the notch later when FaceID demands it. In that scenario, it would be a clear step back in design so they're ripping off that band-aid early.
Consequently, it will probably be quite a while before we see the notch go honestly. There is no telling when, but I think we gotta see FaceID in Macs before we can even begin this conversation.