Unless someone resigns and go to GCAA, Serco will do nothing. If you look at it from their perspective it makes sense not to do anything. It actually makes sense from any perspective. Why pay them to stay if nobody's leaving?
And herein lies the rub. The price of a Serco flat is unobtainable anywhere on your own. Stay in Serco accomodation on their salary and you earn X (take home). Move to GCAA, get more trading beans plus your own palace and maybe take home X minus 2000. If you are already out of Serco accomodation, this whole saga is a no-brainer. As much as it pains me to say it, but Serco is actually in a rather strong position.
If it was me sitting in the support office doing nothing, I would continue to do exactly that, nothing.