I am wondering if it’s possible to enable a type of group voice chat for my forum users, something akin to Discord voice channels.
I understand it’s a huge feature to implement, so interested in knowing the budget for a plugin like this. in the end it will be made open source to benefit the community.
Sounds like you want synchronous real time style voice chat. There is an unofficial Discourse - Mumble plugin but don’t know much about it or if it works at all. 
If you are looking for something perhaps more asynchronous with voice recorded messages, there is this component:
Yes, I saw both those topics but I’m looking for sync voice chat done from browser. That mumble plugin only shows the list of users, to connect to voice you need to download Mumble desktop. N