It would be an interesting precedent, but not unheard of in majors where pass over pay and other such compensations are in force. If your income is reduced through no fault of your own, and no doubt the EZ swiss crews spent weeks on SBY instead, there is a case for compensation.
Now, and here is a thought, over the past few years many F/O's were taken off their rosters to allow new pilot training. Their actual salary was well short of the monthly income they were told to expect when joining. and what their roster originally planned to give them. I wonder if they can now claim lost earnings. They did not receive free time in lieu but spent days on useless SBY.