And no kind of political police is going to become interested?
I have heard that having a degree from a Taiwanese university is somewhat suspicious.
If so, what other than lack of interest stops PRC citizens from learning about the Tiananmen square "mystery" when they travel to Taiwan?
But don't go talking about it in groups. That's how movements get started.
Whereas people searching the internet for 6.4 or 天安门事件 can be expected to have a much higher level of interest in 天安门事件, and need to be suppressed.
Thousands travel daily between Taiwan and the mainland.