If I was a judge, I’d come down on this hard. I’d make an example out of Twitter.
Since Twitter went to court in order to fight for arbitration, and is now refusing to pay for arbitration, I’d treat them like they were deliberately and intentionally abusing the legal system (which they may very well be). I wouldn’t let them establish a precedent of disrespecting the court.
I think a higher court should overturn the judgement requiring arbitration, and let the class-action suit continue.