The absence of the English varieties of (tongue in cheek warning) hockey, shrimp on the barbie, middle earth, etc. on desktop under "User Interface Language" seems like a glaring oversight. I see them listed under "Accept Languages" but I guess that has no sway over spell checking? In a word: weird.
I hope they fix this in an update. And I also hope the orange menace pipes down on his territorial expansion bs. In any direction really but north in particular.
This sounds like a weird person at best or the prelude to a scam, stalking, or social engineering at worst. You stick with your standards and don't doxx yourself to passive aggressive douchebags, however insistent they may be.