I think they were probably built at the same time. I think Quote is an example of a classic silent protagonist. There are a bunch of other characters who would normally be able to talk, like all of the protagonists from the Pokemon series, Link from the Legend of Zelda, and all four warriors of light from the original Final Fantasy. I think I actually read something about silent protagonists before, about how it's indicated that they actually talk, though its supposed to give you a closer connection with the character by having you imagine what they say. Like X-Calibar said, there are some points where it would have been impossible for Quote to have communicated those things to those people without speaking.
And relax about the whole Quote talking in Curly's story thing, guys. It's not like it's canon or something.