https://musicbrainz.org/doc/Style/Specific_types_of_releases/Soundtrack#Work says:

The name of the show or film should be placed in the disambiguation comment along with an additional distinguisher if applicable (often the year). If the work has a descriptive title (e.g. “Love Theme”), it should be included after the show title. If the work was used in a specific episode of a TV series, the episode name may be included as well, enclosed in quotation marks.

First of all, this contradicts the Work guidelines: STYLE-1868

Assuming that this guideline is supposed to override the Work guidelines, then I think multiple deficiencies need to be addressed:

1. This doesn't scale well, or make any sense IMO, for pop songs / compilations.  For example, consider My Heart Will Go On, the work for the theme song for the Titanic film. Everybody knows this recording is on the Titanic soundtrack release, but this Work isn't currently complying with Style/Specific_types_of_releases/Soundtrack#Work.  This work is instead complying with Style/Work#Disambiguation_comment which demands that no disambiguation comment be present.  Which is correct?  Personally, I think Style/Specific_types_of_releases/Soundtrack#Work should not apply to "tie-in" pop songs, and "soundtracks" that are really a compilation of songs from various artists.

2. Personally, I think Soundtrack Style is just asking for noise in the disambiguation comment if a Work has a unique title.  Maybe Style/Specific_types_of_releases/Soundtrack#Work should have an exclusion added that makes it more in-line with Style/Work#Disambiguation_comment - "don't add a disambiguation comment if it is not necessary to distinguish the work from others based on writing credits and recording artists"?  Does this Work really need a disambiguation comment?

3. It gets worse when a Work is included in multiple Soundtracks - are we supposed to include all 4 of these appearances in the disambiguation comment?  The song was introduced simultaneously across multiple films/games. This is not covered by the soundtrack guidelines that contradict Style/Work#Disambiguation_comment. 

4. What about when a Work is used in multiple TV episodes?  Are we supposed to list all of the episodes?  The guidelines say you're supposed to list the TV episode, but don't say what to do here.