I think they made the announcement to give everyone a chance to use the facilities at the airport prior to boarding and to give anyone that may have physiological reasons that they couldn't take the chance, to rebook on another flight. That's as much as they can do short of cancelling. It's been said already but they had a choice to make, fly the plane to SEA, where they may well have fixed the lav issue, on a short 25-30 minute flight or cancel and strand 74 passengers. The answer seems obvious. At least to me.