For several reasons we would always load ogvjs if the browser you were using did not support vp9.
However in testing I noticed that this introduces a huge delay in loading basic mp3 audio clips with videojs, which is actually a pretty common use case, as we have way more audio clips than video clips.
It think we therefore should evaluate for each specific media element wether or not native playback of that set of sources is supported and only if NOT supported, then we should load ogvjs. That way the most common case of mp3s becomes much faster, and only when something actually requires it, we would have to load ogvjs.
This might require some extra promise guarding and expanding the functionality in OgvJsSupport lib