I'm not sure if this is intentional or not. The various stats queries on Special:TimedMediaHandler only includes things in $wgEnabledTranscodeSet, not things in $wgEnabledAudioTranscodeSet.
Its kind of unclear if this is done intentionally. If its not, its a pretty easy fix, if it is, we should have some text on Special:TimedMediaHandler explaining this.
Version: unspecified
Severity: normal