This Article does not apply to any public water district whose territory is situated in 2 or more municipalities, except where one of the municipalities is incorporated after June 1, 2004 pursuant to the amendatory changes to Section 2-3-5 made by this amendatory Act of the 93rd General Assembly. Nothing in this Article prohibits a municipality from continuing to operate utility facilities which it owns and operates, at the time territory is annexed to the municipality, in that territory even though it is part of a public water district.