So you agree that the people have joined a class of people that are allowing one member to file a claim against TheBitMan's parents, and you feel the need to be a pedantic prick, and correct me calling it class action crap...
It isn't a class action lawsuit. That requires certification as a CLASS. Your use of the word "class" is confusing given a lawsuit is a legal action and the term "class" has a specific legal meaning. Only a judge can certify a group of claimants as a class. So someone correcting you that it isn't a class action lawsuit is simply being factual.
The proposed legal action would be a claim in small claims court. There wouldn't be a class there would be a single claimant and one (or possibly two) defendants. Any agreements between other creditors and the filing claimant would have no bearing in the case.