Great!
Now should the Audiobook Style Guide be applied to audio plays, especially the section about the release artist?
IMHO No.
An audiobook has usually one to three narrators who can be listed in the artist credits as " read by XXX". That honours the role of the narrators, mimics how the narrators are credited on the cover and it helps to differentiate between audiobooks of the same text by different narrators.
Audio plays usually have more voice actors and it doesn’t help anyone if they are listed in the artist credits of the release.
The CSG approach makes IMHO much more sense: Credit the original author and the artists that are prominently featured on the cover and/or spine. Use Advanced Relationships for the voice actors.
It would be nice to have a style guide specific for audio plays or at least an amendment to the Audiobook Style Guide. It should also help to categorize a release as audiobook or audio play.