That is essentially the thesis of American foreign policy in Asia since the 1980s. The results have been mixed; yes, they have a huge, prosperous middle class now, yet the government remains about as authoritarian as it ever was.
Now, with technology, in fact things are getting worse. Everyone is required to have a cell phone, everyone is spied upon, a "social score" is maintained and if your score dips below a certain threshold, you may not travel etc.
If the EU thinks that making more trade deals with China is going to temper any of these, they're naive indeed.