I'll take your word for it, but the message that came 'loud and clear' from Boeing was that the intermittent horn in the air could 'only be pressurisation', so that is interesting. However, our drill remains the same - we ASSUME loss of cabin pressure and act accordingly until we prove otherwise. No mention of this 'interlock' in any of our owners' handbooks or our MEL. I guess a failure of the A/G switching in general could produce a warning too when the flaps are retracted.