I would like to think that the list does not include those flights booked through Delta (yesterday) but the first leg of which is on their code share partner Seaborne airlines. I booked their flight through SJU for 3/28. It has a Delta flight number (DL7337) and a Seaborne flight number. Their website today shows nothing available for the 28th, but the 31st is still listed. They only seem to fly this route twice a week.