If I were BA I believe I would leave the offer on the table, and continue with the return of staff travel at its present level for strikers.
Let it lie there, with its pay raises, opportunity for full return of staff travel, etc., to show contrast to the inflammatory rhetoric that offers no concrete results to BASSA and Amicus members.
The problem is BA are almost certainly losing meaningful amounts of advance bookings. I am going to Dubai for a family holiday next Feb but not booking BA just in case. I've been caught before and there will be many like me.
I suspect BA will wait until they know the Xmas period cant be hit and will then go all in to end it.