By all means, provide a change to build depth to a character, but not such that it flies in the face of all that has come before.

And it partly depends on how long a character has gone with no voice. Link hasn’t spoken for 25 years, and he shouldn’t start now. On the other hand, the “Jak and Daxter” series started with Jak as a silent protagonist in the very first game, but he got a voice in the second game. The series changed in a way that it needed a hero that spoke, plus they made the change so early on, it was a good change rather than a bad one. Anyway, I rambled. Interesting post.

I actually wrote a post similar to yours a while ago discussing the pros and cons of having a silent protagonist vs. a voice acted one in games. Silent vs. voice acted protagonist does depend largely on what kind of game it is. RPGs can go either route, but established characters like Link and Samus should probably be left alone. Why fix something that ain’t broke?