Earlier quoted context omitted.
California's rules are explicitly allowed by the clean air act, otherwise they would not be okay. See, e.g, https://www.law.cornell.edu/uscode/text/42/7416 and https://www.law.cornell.edu/uscode/text/42/7402 and https://www.law.cornell.edu/uscode/text/42/7410
Those links are about air pollution not general interstate commerce or Title II.
The post you are responding to explains that the specific type of legislation that the parent is asking about was explicitly identified in federal law as allowable.