More than a decade in BA and my experience is that 6000 employees have been sulky monkeys for that whole time. Only difference is that now they have an excuse. Sometimes you have to stop protecting people from themselves.
A demoralised sulk is worse than a sulk.
BA still have the option of acting out a 'no negotiation' stance. It's on the table where Len can clearly see it. Personally I think they'd be better off in the long run if they played hard ball now and called the bluff of the grumps. Maybe that's what'll happen. Still a long way to go.