Ahhh.. but you forget that
a) Unite have said that it's not about striking, it's about 'sending a message'
b) Len has said that there would not be strikes over Easter or the Royal Wedding
c) BASSA can't call strike dates. Only Unite can. BASSA is a branch.
d) BASSA have said that they don't need to strike, that the threat of strike action is sufficient to undermine customer confidence in BA
e) BASSA have also said that their cunning plan will be to announce strike dates and then call them off at the last minute - teehee.
f) Len has said that they won't strike but use 'wierd and wonderful' alternatives
Now, I'll cheerfully concede that the BASSA branch secretary (for the moment) may wish to run amok with announcing strike dates, particularly as it would seem that he has lost his appeal at tribunal and is rumoured to also have been threatened with arrest by Surrey Police (see the other place for this) . I'm not so sure that the Unite leadership will want to play this game though. The policy of calling strike action may of itself leave them open to penalties under TULRC if the action is seen to be unprotected. Moreover, in the macho game that is trade union leadership, I can't see Len wanting to be seen as backing down on a strike call if he doesn't get a response from BA management.
I would expect Unite to look very carefully at the numbers coming out of the ballot. If they think they stand a chance of bringing BA to a halt, they may go for strike action, but they would need 100% support in the ballot on 100% turnout and be able to convert that into real strikers. The trouble is that they are faced with a workforce that is predominantly female. Now whilst many may like the idea of watching a royal wedding, they will certainly not want to be associated, or seen to be the people who wanted to rain on that event. So any suggestion of a strike on April 29th or the run up to it may well backfire very badly. The public backlash would make the reaction to the '12 days of Christmas' announcement seem like a mild rebuke.
Bob Crowe may get away with it on the Tube, but then tube drivers are mainly male and probably don't care a toss for any Royal Wedding. There's not exactly an alternative for getting around a lot of London. BA is in a very different place.