Android Authority, citing an anonymous source, reports that Google has
introduced the 'Longevity GRF' program which is designed to make long-term
support easier to Android manufacturers.

One of the primary roadblocks for long-term software support on Android has
been the chipsets themselves, as the chipmaker would often only support the
chip for a few years, and Google required updated vendor software with each
new Android update. Google started freezing this requirement a while back
as a part of "GRF" (Google Requirements Freeze), enabling a few years of
updates to be certified without a change to vendor software updates. But
that only allowed for 3 years of updates before things would get
complicated.

In a closed-door meeting earlier this year, Google introduced an update to
this with the "Longevity GRF" program. This allows Android manufacturers to
continue using that original vendor software for up to 7 Android OS updates
instead of just 3 updates. However, these companies will still need to
update the Linux kernel at least every 3 years. This is primarily a
security focus, Android Authority says, as backporting security patches to
older Linux kernels could result in more complex updates, as well as
missing patches altogether.

https://9to5google.com/2024/10/23/google-android-7-years-updates-longeivity-program/