He's probably created an anonymous account because we live in a world where you may well lose your job for even questioning that a _source control branch name_ might offend someone.

An opinion that - in the real world - the vast majority agree with.

Trying to portray the use of terms like master-slave as something that "might offend someone" is a complete misrepresentation of the issue, and one that is spawned from bad faith.

The overall goal is inclusiveness. The goal is not centered around whether an expression offends, but whether an arbitrary naming choice does not help accommodate other people or if it might bring discussions and debates over personal matters some people feel strongly about.

A few decades back, there was a common rule of thumb that was quite simple: do not discuss politics or religion in the workplace. The reasoning is straight-forward and simple to understand: if you wish to work somewhere where coworkers do not antagonize other coworkers for stupid personal reasons then you simply didn't opened the door to discussions about stupid personal matters.