A lesson I learned early in business when I took a contractor to small claims court. "You can't draw blood from a stone".

Coinkite is cooked. They aren't a big enough company to be insured for an incident of this magnitude. Sure you could probably sue them and once they are stripped of their meager assets by a bankruptcy court, creditors are paid, employees are paid etc there is likely nothing left and if there was anything it really would be almost nothing when split amongst affected users.

The only way users could possibly get their funds or a portion of their funds back is if the hackers were caught with the Bitcoin and it was seized by law enforcement. Maybe there would be some sort of path but even that seems pretty unlikely you would have to prove ownership of the wallet, prove that wallet generated that seed, prove you didn't move the funds yourself. Seems pretty unlikely and a high bar to meet.