Why was https://musicbrainz.org/doc/Style/Release#Medium_title modified to say that there are cases where "disc n" are acceptable? I would expect "disc n" to be kept out of the medium title in all cases. (I'd also expect ", Disc n" to be inconsistent with MusicBrainz capitalization standards.)

In my opinion, the purpose of the DISCSUBTITLE/SETSUBTITLE tag that the medium title gets mapped to in file metadata should span multiple discs without being explicitly and intentionally broken by the addition of "disc n" text.