I think we might be the exception, but we were notified 2 days prior to wife's N-400 interview that it would be a combo. We had already prepared for a combo. We were both required to be present, and we both answered questions for the I-751 part of the interview. We sat together for that part.
Dallas Field Office Dec14, 2022
The N-400 status immediately, within the hour, changed to "Oath will be scheduled". A couple days later, the I-751 status changed to "Case Approved".