Graph does, returns JSON with per-attendee status querying
https://graph.microsoft.com/v1.0/me/calendar/events/<event ID>/attendees
See https://learn.microsoft.com/en-us/graph/api/resources/responsestatus?view=graph-rest-1.0
EWS similar (for on-prem, and still EXO)
https://learn.microsoft.com/en-us/previous-versions/office/developer/exchange-server-2010/dd633669(v=exchg.80)