The OnePlus 3 and 3T can now be upgraded to Android 10
The OnePlus 3 and 3T developer communities are still going strong. Despite the devices being released in 2016, there are at least four Android 10 ROMs for both devices in active development. All may have more bugs than official OnePlus Android 9.0 Pie builds, but that should improve over time. The Android 10 projects are as follows:
Flashing any of these requires your handset to be running at least OxygenOS 9.02 firmware and TWRP 3.3 or newer. Having an unlocked bootloader is a pre-requisite too. While official development for the OnePlus 3 and 3T has now ceased, it is great to see communities breathing new life into older devices. If the demand for OnePlus 3 and 3T development remains strong, then expect to see both devices receiving newer versions of Android too.
If you are an avid OnePlus fan but do not fancy relying on community-developed builds, then the OnePlus 5 and 5T will receive Android 10. OnePlus has scheduled the rollout to both devices in Q2 2020.