This subchapter does not:
(1) prohibit an employing entity from uniformly changing the group health insurance plan or group health coverage plan provided for its employees and employees' dependents;
(2) affect the definition of a dependent or the eligibility requirements for a dependent under a plan;
(3) prohibit an employing entity from increasing the cost of group health coverage to its employees and to eligible survivors covered under this subchapter to reflect any increased cost attributable to compliance with this subchapter; or
(4) affect the right of a political subdivision to self-insure or provide coverage under Chapter 172, Local Government Code.