Since Wikipedia can be dumped onto a memory card I am not sure how effective the ban is supposed to be. It will constrain its spread but it is very hard to block all means of transmission of information.
"it is very hard to block all means of transmission of information."
I think this is something to understand about modern political information manipulation/restriction.
The 1.0 version totalitarian censorship aimed for full information control. This is what the soviets and pre-1990s CCP tried to do. It's difficult because (as you say) information is hard to control.
The 2.0 version is about enough control. You can use a vpn (or memory stick), but most won't. This gives one version of events a major advantage over the others. Easy-to-find praise for the government, difficult-to-find dissent.It's about dominant influence, not absolute control. When needed, regimes can temporarily increase control, like erdogan did during the last turkish coup attempt.
A soft paralel is social media "bubbles." They don't "control" the information you can access, but they are enough to influence your opinions in a direction. There are lots of exceptions, but on average, these have a big influence on who we think the good and bad guys are.
How many were already using Wikipedia in the first place? I assume that before the ban happened it was already pretty much hidden from results in Baidu and the like?
You are right but no need for a memory card. Hundreds of millions of Chinese tourists go aboard[1] every year. Most of them travel within Asia so most HN readers don't feel it. Let alone VPN that most educated people can use if they really want to.