Bringing in voice comms is a BAD idea
Before I get people making comments in response to the headline alone, I invite you to read what I say. Several seasons ago, I stopped playing League all together for 4-6 months, with Dota 2 being the new game I started playing. It wasn't that I didn't like league, but my friends wanted to play dota 2. After those 4-6 months, I came back to league and I've stayed here since. Dota 2 had its strengths, but it also had its weaknesses. Take my word for it, comms open up a WHOLE NEW LEVEL of toxicity and frustration. You get accents and language barriers. You hear the hate in someone's voice. And it gives people this sense of entitlement.
Do not bring voice comms to league of legends. There are plenty of options without it that you can use with your friends, but opening up the option to random solo queue players isn't a good idea.