“Those people” can be a racist or classist dog whistle, but isn’t always, and also there isn’t really an alternative.

The vast majority of the time ‘they’ or ‘them’ works in the same sentence as ‘those people’ when refering a goup since you already need context for who you are referring to. I can’t even think of an example where they or them doesn’t fit.

Description of a group of white people from Georgia.

• I heard they like fried chicken.

• I heard those people like fried chicken.

Hell, the second one sounds racist even after making it clear I was talking about white people, and I typed the words!