This is an interesting issue. I spent time in the past, "de-gendering" official documents. Personnel ads, staff contracts, club constitutions, promotional material, and such. I always went for simpler, as long as it was unambiguous.
The history of the terms Master and Slave go back a very long way in history. Some of the earliest writings, which seem to be mainly lists of possessions for the purposes of taxation, makes reference to slaves. It was not until the mass kidnapping of Africans for the sugar and tobacco industries in the Americas that the idea of "race" was introduced, giving the terms their modern connotations. I don't know how far back the English words go, but I would think the terms existed in early languages. Certainly they are there in ancient Latin and Greek.
I've never really understood the use of Master and Slave for HDD's. If it referred to having synchronised spindle rotation, then it would make sense as the terms have been used in servo's for at least a hundred years, but it doesn't. Wikipedia has this:
"In parallel ATA hard drive arrangements, the terms master and slave are used but neither drive has control over the other. The terms also do not indicate precedence of one drive over the other in most situations. "Master" is merely another term for device 0 and "slave" indicates device 1."
Any attempt to remove the terms is going to be fraught with problems. Do we need to make it an international standard? That could mean the US imposing it's view on the rest of the world. Do we grandfather in everything before a certain date? There are a lot of uses in the engineering world, including other than servo's. On the railways, locomotives used in multiples have one with a driver, and even if that is not referred to as the "master", all the other loco's are "slaved" to it.
In electronics, would Primary and Secondary suffice for most uses? I think whatever terms are chosen an attempt should be made to synchronise them with other usages. Thought should be given to standardisation, otherwise we are going to end up with not just multiple terminologies in English, but translations into other languages could become quite fraught if the terms translate badly. This is a good example of the unexpected hilarity that ensues when two people for whom English is not their first language try to make puns! https://youtu.be/9reSQXZy77U
However you proceed I wish you the best of luck, and will watch with interest.