The first generation of the Surface Duo reached the end of its three-year support period, as promised (released in September 2020, support ending in September 2023). The hardware comes with Android 10 and has received two operating system upgrades, currently standing at Android 12L, falling short of the promised three upgrades.
Microsoft rolled out the final security patch for the Surface Duo in September 2023, and there won’t be any further patches. As for the Surface Duo 2, which was released a year later, it has received updates until October 2024, but it is expected to remain on Android 12L. Amid rumors that Microsoft will not continue with the Surface Duo line, the software development team has been reassigned to other projects.
TLDR: The first-generation Surface Duo has reached the end of its promised three-year support period with only two Android OS upgrades. Microsoft released the final security patch for the device in September 2023. The Surface Duo 2, released a year later, has received updates until October 2024 but is expected to stay on Android 12L. There are rumors that Microsoft may discontinue the Surface Duo line, leading to the reassignment of the software development team.