I vaguely recall a few years ago there was a rumour that China might stop allowing the export of vape gear. Can't remember the reason behind it, maybe something to do with the high rate of smoking there. That didn't happen. Didn't they restrict the availability of vape domestically instead?
China was moving towards a more open economical model, but under the current dictator they are moving back to central control, so anything is possible. There doesn't have to be an economic reason for stuff to happen. Maybe The Boss stubs his toe on a disposable someone dropped on the sidewalk and vape is history.
Like others here I don't have to worry about it until I hit 100.
Not that the U.S. has a whole lot of say in Chinese manufacturing, but we recently found (through intelligence agencies) that China's military is roughly fifteen years behind. And horribly corrupt and mismanaged. I think Xi Jin Poohbear has bigger things on his mind than trade policy, like their inability to strike on the independent nation of Taiwan in the event of an uprising.