I’ve also noticed an increase in using “had [done]” instead of [did] in places I wouldn’t expect. I’m sure a linguist could break that down more thoroughly.

Yeah that’s accurate. Or just “bearing balls”.

A steel ball is not a ball bearing. A bearing is something that bears load and allows for motion, usually rotation. There are sleeve bearings which are just one material or journal bearings which have pressurized oil to separate the spinning shaft. A ball bearing is an assembly with rolling elements (balls, rather than rollers). Those steel balls are just called balls. The whole assembly is called a ball bearing. I used to work in bearing manufacturing and they were just called balls.