There should at least be a voice chat implemented in 6v6 skirmish. If you play alone there is practically no way to be able to effectively have a tactic with your team. It works fantastically well in Overwatch and I really do not see why we can't have it in battle modes/skirmishes.
M&B isn't a serious teamwork based game like Squad, nor is it a tactical shooter with a small amount of players in a match. It's 200 players in a chaotic environment, with a young player base. Voice chat would be endless people shouting, screaming, singing, playing songs, it would be an actual nightmare, and trying to mute so many different people with the clunky teammenu would be horrible.
If they do implement voice chat it needs to be proximity only, at least.
A ping system would be preferrable IMO. Last we heard from the developers about this (during beta) was that both VOIP and ping system were being worked on, at the time they asked which was preferable and both were popular.
We did bring up the obvious and rampant abuse that can come with a VOIP system, so hopefully an easily accessible mute button and an option to disable voice all together will be included as well.