In their blog post, they elaborate:

The first priority is upstreaming the drivers that unlock real workloads, including Qualcomm Hexagon NPU support through fastRPC for on-device AI inference and GPU support through Freedreno , Turnip and Rusticl the open-source Mesa drivers for Qualcomm Adreno graphics and compute. ... Out-of-tree patches may help early bring-up, but mainline support is what distribution maintainers and long-term developers can build on across kernel releases.