OnePlus is using a protruding camera to capitalize on screen space here, and plenty of Oppo, Vivo, Xiaomi or even Samsung phones have pop-up, sliding and even rotating cameras now, all in the name of shaving off the top bezel.
The premise of foldable phones, however, is that they'd unfurl into a tablet size display diagonal while staying compact when closed. Screen area should not be an issue, and Samsung still introduced a notch for the front camera, while Oppo now is thinking about pop-up cameras in foldable phones.
Let's not forget that this is the company behind the Reno phone and its shark fin front shooter, so they might very well get on and do this thing. What do you think about this idea?