AMD is into its third generation of RDNA architecture GPUs so Polaris and Vega seem to have set below the horizon for ever.
In recent weeks the company dropped support for those GPU architectures in their open source Vulkan Linux driver, AMDVLK, and is slowly winding down support for these architectures in their Windows drivers.
Under AMD's extended driver support schedule for Polaris and Vega, the drivers for these architectures will no longer be kept at feature parity with the RDNA architectures.
While AMD will continue to support Polaris and Vega for some time to come, that support is being reduced to security updates and "functionality updates as available."
For those with these chips onboard, this is like saying "so long and thanks for all the fish."
For AMD users keeping a close eye on their driver releases, they'll likely spot that AMD already began this process in September -- though AMD hasn't officially documented the change.
Since AMD's September Adrenaline 23.9 driver series, AMD split the RDNA and GCN driver packages, and with that they have split the driver branches between the two architectures.
This means that only RDNA cards are receiving new features and updates as part of AMD's mainline driver branch (currently 23.20), while the GCN cards are on a maintenance driver branch - 23.19.