It's not just a Beijing Olympics idea.
I went to university in the United States. The university I attended instituted "free speech zones" in the wake of the (second) Iraq War. They were initially protest zones, but by the time I was there they had turned into what you basically said - places where students were told to go to express unpopular ideas instead of being allowed to express them in class.
I took a sociology course during my studies, and the topic of abortion came up. Instead of having a nuanced discussion about the topic, students objecting to the professor's view were cut off or ridiculed. One student, trying to articulate their position was yelled at, by the professor, to shut up and if they felt strongly enough to take their position "to the free speech zone with the other Christian fascists and religious weirdos". Every year I was there, the bounds of the free speech zone got smaller and smaller, so there was even less room where unpopular ideas were officially tolerated on campus.
This is part of why I got out of academia. Not because of any institutional bias, but the authoritarian bent of the administration. All of campus should be a free speech zone. (No, disrupting class is not "free speech", there is a difference.)