I know this may quickly get complicated, just putting this out there for future consideration.
End state:
Designate a specific field in a deck that can be used for school-specific or study group specific content. In other words, make it so that some changes are published on a field-specific basis and people can subscribe to extra content/fields for certain decks.
Example:
Say I subscribe to the AnKing deck. Under the Anking deck, there is a list of other fields that I could subscribe to if I wanted. Maybe this is just extra content (Extra field that contains a youtube link to a free video explaining the topic, or some other resource) or maybe it is school-specific content (Extra field that contains a screenshot of the associated in-house lecture).
Pros:
Would allow for opt-in expansion of current decks to include more content that deck maintainers may not care to add.
Cons:
Would be hard (ie, dynamic editing of card types to add in user-dependent fields, sending deck suggestions to multiple maintainers depending on the field, etc).
Caveats:
I’m not sure if it would be better to integrate this into Ankihub directly, or build an add-on that somehow shows extra fields in one view (or combines two decks on ankihub via ankihubID in some other way).