BA have already stated that the cost of any strike will come out of the cabin services budget.
As forward bookings are now decimated and costing the company millions do you think WW will now play hardball?
Its one thing to say that, quite another to impose it. Imposing those costs on cabin crew who chose not to strike would be unreasonable, counterproductive and quite possibly illegal. Not to mention the negative impact cuts would have on the service provided to BA's customers.