An interpretive statement or opinion issued under this subchapter does not have the force of law and is not a rule for the purposes of Chapter 2001, Government Code, unless adopted by the commission as provided by Chapter 2001, Government Code. An interpretive statement or opinion is an administrative construction of this chapter or Subtitle D, Title 3, may be relied on by credit unions authorized to engage in business in this state, and is entitled to great weight if the construction is reasonable and does not conflict with this chapter or Subtitle D, Title 3.