It's solo queue people won't listen even if there's voice chat. Pings and in-game chat are more than enough to communicate strats (granted you can't really adjust on the fly, which is the big weakness). During your League experience, have people always listened when someone pings for something, or types in chat to go to an objective, etc? There's always that one person who doesn't listen because he wants to do wolves or something, isn't there?
Voice chat isn't why people don't communicate well in solo queue. Pro teams who play together a lot have trouble communicating/leadership issues. There's no fix for solo queue communication. You just try to get your team to do something and hope they listen.
Voice chat really won't help these issues.