I think OP was just using the definition of "class" as in a larger group of people that could file a lawsuit.

See https://www.law.cornell.edu/wex/class_action

He's using a specific legal term in the US.

See: https://en.wikipedia.org/wiki/Protected_group

A protected class is a group that is illegal to discriminate against in this manner, in the United States (and several other legal systems).

"Phone OS" is not a protected class. Many other things are, though, such as Race, Religion, Sex, etc... Varying a bit by jurisdiction and legal system.

This is something that's not really worth considering unless you want to pick a fight. You just look it up and see if it is true or not.

edit: Ah, "customer segments" vs. "classes"; I didn't understand the misunderstanding.