There is absolutely nothing illegal in making staff redundant if there is no work for them. With 16 aircraft not flying in the winter one would assume there would be surplus crew. It is unlikely 2000 c/c will decide to leave through normal retirement or for voluntary reasons other than VR. Hopefully 2000 will want to take the v/redundancy offer. I am not so sure this will happen because I have seen that only a few c/c have left in the past few years according to the retirements etc section in the BA news.
I know so many people outside the aircraft industry who have been made redundant recently, few have found alternative employment and are unlikely to do so for a long time.