The Court did not say that the secured bond holders did not have any rights. It did not rule on the merits of that argument. The basis for the ruling was that the bond-holders did not show irreparable harm by letting the sale to Fiat take place.
Perhaps the court thought that in the end it could award the UAW shares to the bondholders. If this is a possible remedy, or if there is another remedy which makes the bondholders whole, then the lifting of they stay does not have that great an import.
Same with GM, and it's pretty much what's been done all along with all the other large bankruptcies the last 20 years.
The law treats these health care benefits as SALARY or WAGES. Presumably the company secured the benefits with its assets.
International Harvester was literally reduced to a successor company with nothing to do but pay the health benefits.
The preferred bondholders would be in line immediately behind workers demanding wages (including the health care benefit).
I suspect the UAW lawyers and grifters are already figuring out how to bleed the new NPG that will be administering the health care benefit.