I'm kind of surprised they aren't reevaluating the use of terms such as "Master" and "Chief".
Edit: My bad, seems it was already touched earlier. Still surprised though!
Chief/Chef are just the English/French equivalents for the title of 'leader' for the communities, and predates colonization of the Americas. There are something like 50 different different nations in the Assembly of First Nations, with a number of unique languages and cultures with their own term for their leaders, and they use Chief/Chef as well when they are writing it in English/French. It's a widely used term all over the place and doesn't have a negative meaning (for example, CEO).
There is a long history with 'Master' tradesman, which meant that you have mastered the skill sets of the trade and were licensed by the guild to have apprentices, and goes from Apprentice to Journeyman to Master titles (before the trade name; ie master blacksmith). It's still used in trades today, and you can become licensed as a master welder, master electrician etc when you demonstrate an expertise in your field and have enough experience. Generally at that point you are inspecting/overseeing other people's work and certifying it meets the standard.
From that context, Master Seaman/Corporal makes sense, as you have demonstrated a certain amount of expertise in your trade and have enough experience to train/supervise people. Not a direct comparison to a master tradesman level (as they'll have much more experience), but that's the context of it. That's still widely understood and commonly used in trades, and is a totally distinct meaning from master/slave.
It's also widely used generally in nautical terms, and the highest level of qualification you can get on the civilian side is 'master mariner', which means they can captain pretty much anything.
Personally, have no objection to the concept of updating the rank names, but if we are going to change it to 1st/2nd/3rd, it's close to the civilian equivalent names but nowhere near the qualification level (ie 4th class marine engineer is the roundsman, and 1st class mar eng is the Chief Engineer) so will just confuse the heck out of anyone outside of DND. It also means every single publication, policy, document, or regulation that references ranks will not line up, so there is a lot of staff time required to update them. Maybe not a big deal if it's done piecemeal along with other changes, but still collectively means hundreds of hours of staff work for something that no one was clamouring for, and will probably take a decade or two before people stop using the old term occasionally out of habit.
I'd rather they devote our time and energy to real, meaningful changes rather then window dressing, and given that this has already generated a few pages of discussion, and hundreds of facebook comments, it will be a real time suck for no real gain.