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.
Cannot reproduce.
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.