Do many people besides fans have to read the words on magic cards? Not really, it's almost entirely fans. So how does "fan words" minimize the importance of acronyms sounding good? A phrase change is basically only impacting fans and the words they use.
I've almost never heard a player say "converted mana cost" out loud in a game, even if all of the cards are actually printed with "converted mana cost". They say CMC. I say CMC. Now I have to decide whether to say "CMC" or "MV", and personally, "MV" sounds a lot worse to me (a fan).
The following are my personal experiences
I have played the game since it’s beginning and therefore also been around for the entire converted mana cost era and I have never heard anyone say the letters “CMC” out loud. I think that must be an American thing. They didn’t do it in Gernany, Sweden or Spain either or Denmark where I am from. I often see Americans write the short version but I actually never thought you said ‘CMC’ out loud since it takes about as long to say as ‘converted mana cost’.
Do you also do that with everything else? I know you don’t say Federal Bureau of Investigation which makes sense because it takes so long to say.
I have also never heard anyone say RFTG or RFG (Remove from the game) but I hear people say exile. I also never hear people say out loud BoP but instead they say Birds of Paradise. But they write BoP.
I could be wrong. These are only my personal experiences but they expand over more than two-and-half decades.