For Surface devices the "device support period" means the period during which Microsoft will provide driver and firmware updates for a device. The device support period kicks off when a device is released. However, after an end-of-device-support date is reached, Microsoft will continue to provide Windows OS feature and security updates in keeping with the Windows 10 lifecycle policy, officials noted.
The earliest Surface models, like Surface RT and Surface Pro and Surface 2 received five years of driver and firmware support. More recently introduced devices are largely getting four years of device support.
Microsoft officials state on the docs.microsoft.com Surface driver and firmware page that Windows-based Surface devices that "Surface devices will receive driver and firmware updates for at least 4 years from when the device was first released." In some cases where support is longer than four years, Microsoft says it will provide an updated end-of-servicing date in advance of the last date of servicing.
End-of-device driver/firmware support for a few of the newer Surface devices:
Surface Laptop 3: October 22, 2023
Surface Pro 7: October 22, 2023
Surface Pro X: November 5, 2023
Surface Pro X SQ2: October 13, 2024
Surface Go 2: May 6, 2024
Surface Laptop Go: October 13, 2024
For the full list of Surface device support dates, check out the driver and firmware lifecycle support page here. And just to reiterate, Surface users can continue to use their devices safely even after the end of driver/firmware support period expires, as they'll continue to get Windows 10 security updates.