I am sure the union bosses know what that is, but they don't care since they continue to draw a paycheck even when the workers are on strike, and when (and if) they go back to work, the union will just take more off the top.
The workers in the grocery store strike in CA "won" concessions that would take 10 years to repay the pay they lost during the strike. Got any bets on if they wind up on strike again before their last strike pays for itself?