If this old comment is still accurate, then it seems ffmpeg isn’t a mandatory package within the Multimedia group.
My bad, I think I completely misunderstood this. So because --with-optional is included in this command sudo dnf group upgrade -y --with-optional Multimedia it will install ffmpeg-libs anyway.
So that means if I used that command ffmpeg-libs would already be available, making libavcodec-freeworld unnecessary?