A new co-worker who is not a native English speaker uses "you people" whenever referring to a group. As in "This quarter was great because of you people." If something negative happened "You people did not finish X, Y, Z?"
Part of me says to say something 1:1 like "You people is an insult in America, you should use 'you all' or 'y'all'". Part of me also says to say nothing as I don't want to become a language coach.
Should I mention it, and how is the best way to phrase this?
For those outside the US, the exact words "you people" have become an insult. See https://www.yourdictionary.com/you-people
NOTE: I am a native English speaker, and do not believe the co-worker means this as an insult.
EDIT IN RESPONSE TO COMMENTS:
To the average American English speaker, "you people" is perceived as an insult. I do not believe the speaker was racist, only unaware.
The phrase originated as a racist insult implying the speaker and receiver were part of different ethnic groups. It has since become an insult implying the receiver is an outsider from the speaker's desirable in-group.