Even then it might not be possible. This is a binding arbitration award. I think only the arbitrator could change it.
To add to this I have heard that the company will not make a major wide body purchase until the fence is gone. The fence actually contributed to saving the 747-400. Absent the fence it may well have been gone by the end of next year and replaced with 777-300's. The company realized that they faced a nightmare situation if they attempted that. They would have two different 777 categories at the company and never the two could cross. Have a mechanical on a 777 in NRT and want to move another to that flight. Nope, ones a FDAL and one is a replacement FNWA. Need to reroute a copilot in NRT to replace a sick crewmember. Nope wrong sides of the fence. Need a shortcall reserve to cover a China flight from DTW, Oops out of short calls on that side of the fence. So sad flight canceled. The problems with this situation go on and on hence the extension of the 747's for exactly 5 years. Look for them to go fast at that point and a bunch of 777's to show up.