Hey @mcrcruiser even if your cabin is not ready, you will be able to drop your stuff in your cabin then head out to eat. We very much enjoy MDR lunch on embarkation day - never crowded, so, as others said, it's a nice calm in a frenzied morning. We've never been kicked out of MDR and just enjoy the view (ask to be at window if they don't put you there) until we're ready to head to the cabin.
Last we sailed from San Diego was Dec 2022 - no issues.
Safe travels - enjoy your cruise!