In reply to those two points:
1) What change can overcome the continued oppression of an entire people?
2) Forget atrocities, do your sources convince you that Tibet deserved or wished to be invaded, conquered and ruled by China?
If “oppression of an entire people” means the same thing today as it meant 20, 30, 40 years ago or more, then one can only conclude that the Chinese people are immensely less “oppressed” than they were in previous years.
China claims territorial possession over the area known as Tibet. Maybe they’re wrong. I know that America has also claimed possession of lands claimed by others. Maybe we were wrong. But the reality today is that the world seems to recognize China’s sovereignty over that land. If some Tibetans disagree and wish to engage in violent acts to undo what has happened, that’s fine. But I wouldn’t expect China to allow them to do this.