no that is not how it works.
They are now on notice, they have to file a “proof of claim” and if needed an “adversary proceeding” inside the bankrupcty court.
If they do nothing their claim is precluded permanently.
finito.
Keep in mind a creditor who is unknown can cause a case to be reopenened at a later date and dicharged as were all the previous creditors.
Which is why the three boys should have waited until the last possible minute to file.
Well Done.