Notch will not cut any content, it will only be for the menu bar.The problem will be with full screen apps (video, films, and even spreadsheets and other apps that use the real estate). The notch will be very intrusive. There should be a way to reduce the displayed area so the notch does not cut into the content. It might be possible to do that when going into full screen mode and still have 16:10 (if I have it right, there are about 100 "spare" pixels).
The display will always display 16:10 content.