Miss M
You stated you (and presumably everyone else with you) were recruited to fly long haul routes only. i note you state you have been with BA 15 years.
Perhaps a glance at your contract might be useful to you, as so much has been said about contractual matters.
I think you might find your contract states you can fly on any route and aircraft type operated by BA. You and others' with you were recruited on to long haul flying because that is where BA had the vacancies when you were recruited.
There were people who could only fly long or short haul when we were 2 seperate airline which were called BOAC and BEA. I was one of those people.
BA is one airline now, we moved away from BOAC and BEA 1978 ish.
There are some very experienced cabin crew both currently employed as cabin crew and some ex cabin crew in other jobs who would jump at the opportunity to join New Fleet. BA would have no problem finding SCCM for their new fleet, there are 100's of them out there in-waiting.