The Shuttle pilots may be stepping on their own "member" if this succeeds. Not ONE of them was on the Eastern Airlines seniority list after they resigned their position to go to the TRUMP Shuttle (separate company from Eastern with a separate operating certificate.) USAir did not acquire the any portion of Eastern Airlines, they acquired the Trump Shuttle. I'm not sure of the date of incorporation of the Trump Shuttle, but it would be ludicrous to argue a DOH based on a resigned position and which predates the existence of your the employer which was acquired. Should be interesting.
Their argument, of course, will be that Trump recognized their Eastern DOH. That's fine (sounds like DOH was a bargaining position?) Does that mean I can start a new Part 121 carrier tomorrow and give all my employees a DOH of December 17, 1903 (Kitty Hawk) and then when bought out, expect the acquiring company to give credence to that DOH? Same argument the Shuttle pilots are making, simply different degree.
And the Empire pilots might have a better argument, except that their DOH started when they were Part 135 flying Navajos and Metros. That will become and apples vs. oranges argument. This will then open the door toe Piedmont Aviation part 135 types looking for their DOH, as well as the wholly-owned commuter types who later went to mainline looking for the same thing. I doubt the judge will open that can of worms.