There is no report of putting people in jail when they caught buying a cryptocurrency. The news says China plans to cut off domestic access to digital plaforms and exchanges that enable people to trade digital currencies. This apart from earlier report of sweeping bans of local exchanges across the country and restricts their citizens from joining ICOs. Many chinese are also cryptocurrency holders and there still no report of arrest if ever owning a crypto is already punishable by law in their country. There are also reports that bitcoin trade goes underground after the crackdown.
I heard from news that China is banning bitcoins and exchanges but I don't think that Chinese won't make ways to buy crypto. As crypto is decentralize so there is so much ways for them to buy if they really want to. But with the situation that they will put in jail if they caught I think that there is no still regulation to that.