A VPN will get you a few research papers, and some insight into the world outside, but it won't change common attitudes within the country, which will be shaped by a controlled information system.
Having a 'hole' in the information firewall can be useful for some things, but it's still a marginal effect.
Most of the population won't have any use for it - they'll have no reason to question what's in the mainstream.
When Xi bans any negative mention of him, or any mention at all of taboos subjects i.e. Tiananmen, or any material discussion at all of sensitive issues like Taiwan, Uyghurs or Tibet, Hong Kong, anywhere, at any time - then he'll effectively convince the general population of his will on the subject.
The population will ,by and large, believe what he wants them to believe, most people wouldn't consider dissent on the issue because there would be no point.
There are some people within every population that will chose to 'look outside' and 'seek unpopular truths' - but the mainstream population will take care of suppressing them.
Xi could do anything he wants to the Uyghurs, he could subsequently justify it in the press irrespective of how truthful that information was, and the general public would be fine with it. The small number of dissenters would have no means to disagree.
When you combine information control with the fact that there's a lack of any right to organize or assemble, then you have total control. FYI - this is why 'freedom of assembly' is a primary right in all modern constitutions, it's mostly a means of organizing around information.
Finally, it would be incredibly naive to not grasp the implications of this regulatory movement which further entrenches total government control of information, without any oversight whatsoever.