It seems fairly common for companies to deny and disclose requests from the US government. Not only is it a good publicity stunt advocating free speech / privacy, but what can the government do if it's not illegal content?

If the provider in question is hosting publicly visible pages with "offending" content, then of course anyone is free to "report" it or "request" it. If the provider is hosting end-to-end ecrypted data, then nobody should have access to it other than those with the proper keys. That includes the provider of the services. In that case, the provider can only say no to the gov't requests. If the provider has a different version of their platform available in China so that they conform to CCP demands of being able to access user content, then the provder would be lying to the US gov't request for access to user data too. So the suspicion that a US company operating in China with CCP approval immediately brings doubt onto their entire "we protect user privacy" into question.