As someone who has actually used douyin (about one or two years ago) I can say for certain that that isn't true in the general case. Perhaps the rules are a bit stricter but I saw absolutely zero educational content at all in any form. I did see some military videos which seemed like propaganda as they showed up randomly but its hard to say if those only showed up because I watched the first one to its end for example. The only possibility is that they only enable the education mode if you are actually located in China or if you sign in as a child or something. But it didn't seem to be the default experience from what I saw first hand. It shows you want you want to see.