The numbers (of mechanics working forced overtime) were small but the concerns were large it could increase. This was a major issue for members and these talks aren't held in a vacuum.
Up until this point there has always been an exit that allowed the talks to go on, the prospect of additional time. With that removed, this will be a different week of negotiations, one that hopefully will produce an agreement.
The fact that they're here and we're here to talk with the mediators shouldn't be just a formality,