I would not expect any "moves" from BA, they have what they want. They have the savings that they need going forward and MF is being introduced.
BASSA are in a difficult position, they have to do something or this all dies a slow death.
If they do nothing they effectively sign their own death warrant. Having failed to achieve anything meaningful by this IA and giving in, crew will see them as ineffective and numbers will dwindle, though who will benefit from that CC89 or the PCCC remains to be seen.
Crew that commute by air and need ST to do that viably for the long term need some hope that they will get their ST back - even in some limited fashion, or they will have to consider their long term future with BA.
My gut feeling is that BASSA will have to do something before BA but what can they do that will achieve anything of value I am not sure. IA is at its most effective when used as a threat, I'm not sure that BA believe anymore that BASSA IA is an actual serious threat anymore. The classic "I am voting for a strike in order to force BA back to the negotiating table" has been proven to be a paper tiger. BASSA need a viable threat, if they do not have one they have little to bargain with. The members of BASSA who are most affected by IA so far, are probably now the ones that need a successful resolution to the dispute. This also puts pressure on BASSA to come up with something.
Quite what that action is and how successful remains to be seen.