Branch vlc-3.1x with ffmpeg/libva support bumped to accommodate with modern API.
Keep a dedicated ffmpeg5vaapi branch on top of (regularly rebased on) vlc-3.0x with patches that distro maintainers could conditionally apply, assuming ffmpeg5 and modern libva ?
@kwizart noboby will prevent you from setting up a branch for Linux distributions to cooperate, on this Gitlab or elsewhere.
But code doesn't get written by incantation. If nobody writes the code, it's rather vain to discuss hypothesises of how official and officially supported the hypothetical branch would be.