Unclear what a membership event means in the case of changing global profile info

[TheArcaneBrony]

Link to problem area:
https://spec.matrix.org/v1.13/client-server-api/#events-on-change-of-profile-information

Issue
Noticed that some homeservers don't clear the reason field of a membership when updating one's global display name.

After some discussion, some homeserver implementation maintainers and I agreed that the spec is ambiguous on what to do with other fields in the membership events.

Should this be a new event? Should servers automatically clear some fields (reason, is_direct, join_authorised_by_users_server, etc.)? How does this work with custom profile fields (ie. room level overrides for custom profile keys)?

[richvdh]

Noticed that some homeservers don't clear the reason field of a membership when updating one's global display name.

Not really following. Presumably, if you're updating your display name, the previous membership event was a join. Why would a join event have a reason property?