(a) This code does not invalidate:
(1) any provision in an insurance policy, employment contract, bond, mortgage, promissory note, deposit agreement, employees’ trust, retirement account, deferred compensation arrangement, custodial agreement, pension plan, trust agreement, conveyance of property, security, account with a financial institution, mutual fund account, or any other written instrument effective as a contract, gift, conveyance, or trust, stating that:
(A) money or other benefits under the instrument due to or controlled or owned by a decedent shall be paid after the decedent’s death, or property that is the subject of the instrument shall pass, to a person designated by the decedent in the instrument or in a separate writing, including a will, executed at the same time as the instrument or subsequently; or
(B) money due or to become due under the instrument shall cease to be payable if the promisee or promissor dies before payment or demand; or
(2) an instrument described by Subdivision (1).
(b) A provision described by Subsection (a)(1) is considered nontestamentary.