ExXB,
I don't really think they wanted it locked to stop people posting.
What they were worried about is that it might be deleted completely and they were trying to request that rather than delete the whole thread, it just be locked instead.
Not Langley is correct, the vast majority of cabin crew do not talk about the dispute, most just want to get on with their lives and discussing it is now counter productive to a good working environment.
It seems to be others that still want to discuss it all the time and most don't have any conection with BA other than being interested passengers of ours.