I always have a hard time explaining to people carefully writing pagewalls that throwing out 90% of it would actually be more effective...
At the end it boils down to the truth that a Corporation is a hive mind, an intelligent machine ruthlessly optimizing for stock price and profits at the expense of sometimes human values.
What's not immediately clear is that the video (and channel) now shows up in search results. You won't be aware of that unless you either have a clear mental model of the platform, or try to search for the video title yourself (which implies a certain sort of mental model to be present already).
Sure, people only skim and headline-read articles, but because most articles are shit. That doesn't mean people don't ponder at least a bit when faced with a YT upload page. (And the upload through mobile app is probably more common for non-pro [first time, casual, accidental(!?)] youtubers, there the privacy: public field is pretty visible, legible and explicit.
They can mean anything in people's mind, public is that yeah anyone I send the link can see it, but that's not exactly YT's fault, that people don't make the connection, and somehow live in a fantasy world.
And I cannot blame them too much. People are constantly bombarded with misleading messages (e.g. ads), clickbait stuff, terrible UIs, indecipherable contracts, countless pop-up notification and warnings, opt-out and other "dark patterns".
(disclaimer: personally, I read contracts and agreements and it's often pointless and frustrating)
After working in tech for long enough, you realize that no one reads anything, even if its absolutely clear in the UI. And they will blame you for it.