Bob,
I'm certainly not a jailhouse lawyer, but I think there may be two things at work.
1 - I think "abrogating the contract" really means imposing a contract that management wants. The union isn't decertified or anything like that, so there is still a contract between the company and union - just one imposed by the judge.
2 - Under the RLA, at least, the union can "assess" non-members what are in effect union dues. I, too, live in a "right to work" state, so I don't have to pay the dues. However, I have to pay an equal amount in "assessment". Since I'm paying anyway, why not join and have the full benefits (in my case legal and medical advice/assistance if needed with the FAA).
So, yes, they could move the work somewhere and quite possibility end up hiring a bunch of new people off the street at entry level wages. But I think the union and a contract would still be in the picture.
Jim