I think it is unlikely that we will stop using our voices any time soon as we don’t have a replacement for talking to people when actually face-to-face. And I love talking!
An important point about evolution is that an organism changes over time as competition makes certain adaptations better than others and more likely to be passed on to any offspring. A predator that is faster is more likely to catch its food, so is more likely to survive longer and have faster offspring. With humans, I think changes to our hands are only going to happen across the whole species if there is an advantage to having a differently shaped hand. I can’t think of any reason why a differently shaped hand would be better, especially as the things we use most with our hands now, like phones and keyboards, are designed to fit our hands easily. Even if a person with fewer fingers found texting on their phone easier, would that help them survive longer?! Only if we really start to run out of food and resources could that be a real problem. But then why has this guy with no food got a smart phone?!
This is why I think it is unlikely we will lose any body part that we don’t use any time soon (like why we haven’t lost our appendix) – there isn’t competition to survive among people and we have adapted the world around us to suit the way we work (handles on doors for opening, shoes to protect our feet, phones that fit in our hands, voice-activated technologies).