This is very unlikely in any circumstances.

When the Chinese government bans exchanges, or even every single country in the world bans exchanges (which is not going to happen), then people are simply going to trade with other people without an exchange as a broker.

Or, they could use p2p sites such as localbitcoins, or even bisq. It will not affect how bitcoin is operated. It might have a negative influence on price, but that would be all.