Youtube still shows dates for "Premieres on..." in MM/DD/YY, regardless of the locale. Internationalisation and localisation are such hard problems that even the big FAANG companies fail at it.
Yes using JAN FEB etc. would be a very effective quick and dirty fix. I guess the only reason why not many complain in this case, is that "premieres on..." is a feature that almost no one uses on Youtube.
But why people don’t use JAN / FEB / MAR … DD YYYY, IDK, seems low friction and no one gets confused even if they would rather see 7 JAN 2022