Is Linux going to be next? Let's ask Mr Torvalds nicely to remove all master / slave references in the Linux kernel because it is 'offensive'. /s I don't think such a request is practical given the kLOCs of those references which will break other software.
Because anything using the word master must exclusively imply a slave. What about master/apprentice? Maybe the naming of stuff isn't the problem but the lenses that people view things through that distort reality into some stereotype? The glass doesn't have to be half empty. There are infinite colours between black and white. Racism is a behaviour of people and people's behaviour is governed by how they view the world around them.
I've been using git for a long time and this is the first time I have ever considered any sort of racial connection to the naming of the master branch. Last I checked master has more than one definition in the dictionary - which by the way might actually be something worth reading instead of pointlessly causing drama for the sake of marketing. Because let's face it - Microsoft didn't just pull this stunt because they decided to be noble.