I've never seen an in-game voice chat feature you couldn't opt out of. For that matter, even in MMOs with random parties (like FFXIV or WoW) voice chat is usually just not an option at all. You'd have to have formed the party yourself for that option to even exist.

I see this argument pop up every time someone so much as thinks about in-game voice and it's silly every time. What do you think is going to happen? You're going to join a DF queue, pop into Sastasha, and suddenly three 8-year olds are screeching at you? No. Not what happens. Even in games with built-in voice.