I'm surprised Russian isn't on there.

If this is correct,

https://en.wikipedia.org/wiki/Catholic_Church_by_country

There's only 717,500 Catholics in Russia.

Although, careful with this table - it says there's 660,439 in Saudi Arabia - which must be foreign workers, ie not Arabic speakers.

A big one missing is Korean.

Why? Most Russians are Orthodox, not Catholic

Most Arabic and Chinese speakers are not Catholic either.

The Vatican has shown a persistent interest in Russia, and yes, there is a significant Russian speaking Catholic minority, as well as a potential convert base. If I remember rightly, Russia (or the USSR) gets a prominent mention in the Fatima narrative.

Russian has declined a lot in importance over the past thirty years, but it is still a major world language in terms of its spread. It is a surprising omission.

Egyptian copts and XuJiaHui cathedral attendants would like to have a word with you.

I'm already aware of them. They are minorities, as are the Marionites. The Copts are not Roman Catholic. They are long established minorities as are Russophone Catholics who date back over two hundred hers.

The Vatican cannot operate officially within the PRC, but I appreciate the real situation is more complex.