The status quo is that you only need some minor skill at language games to talk about forbidden topics without using any keywords that trigger censorship. With a ban in place, at least one of the participants additionally has to circumvent their country's firewall to reach the other side. Censoring censored media even more is not a good way to fight censorship.
I'm also not sure why you think "How much time would you really spend discussing Tiananmen or criticizing the CCP?" is talking about TikTok, since you can absolutely do that there https://www.tiktok.com/tag/tiananmen
Ideally people would stop using it by choice. Perhaps too much to ask, but I know enough people that wouldn't use it precisely because of these issues.
Agreed that it is easy to play language games, but maybe your intention is to draw attention of a larger crowd that would be completely oblivious to it.
Trying to "win the hearts and minds" of the Chinese people is a lost cause. Either they agree with the CCP or they've adapted to its restrictions. All we can do is try to keep that ideology from spreading beyond their borders.
In my opinion, absolutely. Stop it now before it gets too powerful to ban. WeChat already has 19 million US users.