It just took some time for smarter officials to join in and explain to everyone in power, that by letting the Chinese people pump BTC, will only make money flow out of China and into the pockets of westerners who own most of the coins in existence.
That is the reason why China and Russia wants nothing to do with bitcoin but the western powers don't mind.
Exactly! But that won't stop you as an official working in the Chinese Central Bank to cash in, by shorting right before releasing some bad news. The price swings are pretty big. You could easily make lots of cash by doing so... and NO ONE will ever be able to bring you to court or accuse you of anything.
It is possible, but improbable that someone would take the risk. If the ideology is against bitcoin and you'll caught with doing shenanigans with bitcoin, while being a public official, then you don't have a future in China anymore. And it's not very hard to get caught for doing this.
I find it more probable, that PBoC is just gradually toughening the laws to save face and to lower the chance of an public incident. If they would have frozen all of the accounts + banned all the exchanges in one fast swipe, then this would have created an incident with a lot of public outcry about the hardline politics of China. It's more convenient to enforce the laws gradually, so bitcoin will just slowly die in China without a major incident. If I would like to root out bitcoin, then I would use the same soft tactics, so that the bitcoin enthusiasts couldn't spin the story in their favour with presenting themselves as martyrs.