I suspect upvoters did not attempt to reproduce, which is why everyone saying this is a thing is using a secondary source instead of posting their own screenshots.
The cause is worthwhile but this is just a self promoter who knows that certain sections of the internet are gullible retransmitters for certain memes. Flagging the submission.
Visibility is in general controlled by the uploader, so without evidence that the website was preventing her from changing it, it seems much more likely that she just hit the wrong button and blamed it on Youtube before realizing her mistake.
I would flag this submission for misinformation, but then those ideologically aligned with the tweet would claim even more "censorship" and double down on their incorrectness. This is why dealing with wrong information, lies, and misinformation on the 'net is such a tough nut to crack.
The video is essentially hellbanned.
[edit] It’s listed now if I click back to Park’s account page. Glitch or anti-Streisand maneuver? Impossible to tell.