They are required to negotiate; they are not required to agree to anything.

However, you raise a good point. Ever since the merger us transplants have gotten a steady diet of the collaborative environment between ALPA and management (as opposed the the admittedly adversarial one at NWA). We are finally at a point where the rubber meets the road. Should this TA fail, we'll all find out if this tire has simply been rolling down a one-way road this whole time.