If a beneficiary refuses to sign the waiver stating they believe this will is the will of the deceased so an executor and can deemed.

There is no such waiver.  When there is a Will which has been submitted to probate (proving that it is the Will of the person who died), the court-appointed executor (usually the person named in the Will) or that person's attorney sends a copy of the Will and the court's Order to the named beneficiaries. If someone wants to contest the Will, they should write the court after the Will is submitted for probate and before the hearing at which the court admits it.