Given the threat, I don't think you're likely to see US helos (or ships) operating in the Chinese littorals.
As much as I dump on HSC, I think it's a valuable mission - who says we will end up fighting China in China? Who's to say it won't be a fight in any number of smaller islands, or at least several fights at once that include many smaller islands. It's not a hard scenario to imagine given their 9 Dash Line and the investments they are making all over the Pacific (and Africa and the Middle East for that matter).