The prospective designation in a will or other instrument of an affiliated bank of a subsidiary trust company as fiduciary is also considered a designation of the company as fiduciary and confers on the company any discretionary power granted in the instrument unless:

1. (1) the bank and company agree in writing to have the designation of the bank as fiduciary be binding; or
2. (2) the creator of the fiduciary account, by appropriate language in the document creating the account, provides that the account is not eligible for substitution under this chapter.

Acts 1997, 75th Leg., ch. 1008, Sec. 1, eff. Sept. 1, 1997.