The master/slave naming seems clearly outdated to me and this one is a direct reference to slavery. A better word like replica exists so I'm using that instead. This makes a lot of sense.
On the other hand there's efforts to rename white/black list or the "master" branch on git. I've never thought of these as even being related to racism until people started opening issues on Github projects about that. A master branch in this context is just like a vinyl master, or a master class to me. The final finished product and not any kind of reference to slavery. Am I wrong?