I know people can move their coins to their own wallets, but that is if the exchanges can provide them with the private keys and if they are proficient enough to manage their own wallets.
What?
Have you made at least one transaction using bitcoin?
Why would they need to give away the private keys and not transfer the coins to the address they owned when they deposited the coins or to one they magically acquire when they install a wallet on their phone / computer?
Coin in exchanges are not stored in separate addresses only in a few called cold storage.
The whole idea of sending users private keys is hilarious.
The ban will not be forever. I think the main reasons for the ban are to protect Chinese investors losing money on potential bad quality ICOs and to control the money from going out of China without the "proper" channels that the government allows (mainly for taxation control). The government thinks that the ban is a quick fix before they can come up with appropriate regulation.
If thy do intend to control the cash flow then no regulation will help them.
You can't control bitcoin transactions, you can't control coin to coin exchanges and they will never be able to fully and successfully monitor the blockchain and associate every address with the Chinese owner.
It's a battle they are going to lose from the start. Actually they have already lost it.
