The only instance I can see this is if a game requires a new Vulkan extension, which wouldn't need a new kernel but would need a new Mesa version to provide that extension. For the most part, games use established and standardized APIs (OpenGL, Vulkan, Direct3D) to utilize the GPU and as long as the driver implements the APIs used by the game, the driver doesn't need to continuously update in order to support game updates. On Linux, the driver doesn't handle Direct3D anyways and an intermediate layer (DXVK or VKD3D) is used to translate Direct3D API calls into the Vulkan API. Vulkan does support extensions which are added every so often to provide new interfaces and the userspace portion of the driver (which is responsible for compiling/translating Vulkan API calls into raw GPU instructions) needs to be updated to support these, but also sometimes these extensions are optional and games can use less optimized code paths to work around missing extensions.

It is definitely relevant if you buy new hardware when it's initially released, although Mesa devs seem to be getting better at having it mostly ready by that point. I know historically there were times where you really had to be at the very bleeding edge, and updating to the very latest kernel and firmware was necessary.