Yes, if your criticism of China is in the news they might not let you in. That doesn't apply to many people but it's still a helpful clarification.

>There are other people like John Cena apologizing for saying something "wrong" in English but no idea if they were threatened by CCP or by their managers

Managers, and the reason isn't out of fear of legal consequences but fear of boycotts. Chinese have often felt like those in the West are talking down to them or being condescending, and they've never in their life had the ability to affect those doing so. Now that people really want access to the Chinese market, it's the first time ever for many Chinese people that they feel they can have any impact on how Westerners talk about China or the Chinese people. As a result (and because China has domestic equivalents of everything), Chinese people can be very boycott happy. The government can stop Chinese people from organising boycotts & very often does so (once again, they have an issue with any sort of mass organising by default), but the government can't force people to buy tickets to John Cena's movies & they didn't view it as appropriate to censor the videos of him screwing up what he meant to say. An organic boycott by the Chinese market is the worst nightmare of a lot of businessmen because the future of their business relies on selling in China, so they'll be even more strict on their people than the Chinese government would to try to avoid that.