Selfie cameras that can hide under display panels are probably the natural evolution of the current punch-hole trend in smartphones. Huawei has reportedly filed patents for devices with this technology. Their similarity to the current P and Mate series may raise hopes of their forming the basis of real-world products soon.
https://www.notebookcheck.net/Huawei-patents-what-look-like-flagship-phones-with-under-display-cameras.467642.0.html