We are still waiting for the launch of 2019 iPhone models but rumors for 2021 iPhone series has already started.
As per 9to5mac, Apple can reintroduce the Touch ID with an in-display fingerprint sensor in its 2021 iPhones. The 2021 iPhone models will come with both Face ID as well as In-display touch IID fingerprint sensor.
Apple is working on the technology for the past couple of years but still facing some challenges to implementing the technology in the phone. Current in-display technology has some limitations that include power consumption, the sensing area’s small size, the thickness of sensing modules and production issues. The company is likely to figure out technical problems it’s been having with the in-display components in the next 18 months.