Yeah it was the other way around. As I remember it, libav devs were pretty hostile towards ffmpeg and refused to pull anything from it while the ffmpeg maintain

Yeah it was the other way around. As I remember it, libav devs were pretty hostile towards ffmpeg and refused to pull anything from it while the ffmpeg maintainer kept cherry-picking from libav for a long time after the fork. IMO it's probably the primary reason why libav is practically dead now.