The prupose of the form is to prove that those that are to receive finds from the estate - as ebenficiaries, creditors, etc.,  - have in fact done so.  The form is required by the Probate courts and if you do not sign it the Personal Representative of the estate can indeed come after you to force a signature.  If ther are other ramifications - like being held in contempt of court if you refuse - is unclear to me but I would not be surprised if the court can act against you.  Why take the chance.