A trustee of a trust that is sought to be terminated, modified, or revoked, in whole or in part, pursuant to the terms of this subchapter, may rely on general family benefit accruing to the living named beneficiaries and their families as a basis for approving, or not objecting to, any such revocation, modification, or termination and, in so doing, shall be immune from liability to future claims of any unnamed, legally incapacitated, unascertained, or unborn beneficiaries.