My experience of previous IA was all staff travel privileges removed for a period of 1 or 2 years for all strikers, but returned with full seniority
My experience as a spouse of BA staff is that ST was returned immediately on settlement of the dispute, with full seniority. (3 times to my spouse)
My point was not so much the right or wrong of removing it permanently, which a court will decide, as to show why CC would assume removal would not be permanent whatever BA said beforehand. BA have always said it, yet always given it back. So CC weren't just believing BASSA and it's '5 minutes' claim, but going by history.