(a) This subchapter applies to a 9-1-1 region:
(1) in which the total population served by the 9-1-1 system operated through a regional planning commission was less than 1.5 million on September 1, 2015; and
(2) in which the governing bodies of each participating county and municipality in the 9-1-1 region adopt a resolution under Section 772.604 to participate in the district.
(b) This subchapter does not affect:
(1) a public agency or group of public agencies acting jointly that provided 9-1-1 service before September 1, 1987, or that had voted or contracted before that date to provide that service;
(2) a district created under Subchapter B, C, D, F, or G; or
(3) the distribution of funds under Section 771.072.