According to reports from China, Apple will start mass-producing displays with an in-screen Touch ID sensor that will complement Face ID in anticipation of their inclusion in the 2021 iPhone series. The upcoming displays will likely have a custom Qualcomm ultrasonic fingerprint sensor, which will have a larger recognition area than comparable sensors found in current flagships like the Mate 20 Pro, P30 Pro and Galaxy S10 series.
https://www.notebookcheck.net/Under-screen-Touch-ID-Face-ID-iPhone-to-enter-mass-production-by-2021-New-report.428725.0.html
Too late not to mention quite useless, failing to liberate the screen estate yet adding another sensor taking up space. Is this some excuse to further reduce the battery size?