Discord was more developed for gamers - I think, as an alternative for team speak. So the difference to whatsapp is, that you can have several channels per group with different access rights, plus group voice channels.
So, it's like whatsapp with more features.
I assume that's part of what's being discussed by the admin teams and why its not as simple as setting up a static single room text channel.
Its hard to moderate voice chat as once said, there is no way for OP's to review/replay voice chat if they are not present and active in the chat room when something is said.
In the past we could review our text based chat (IRC) where active OP's can scroll up to reread and we had bots record the chat so it can be reviewed by the Master of Chat and Dir of Mods/Ops as needed.
I could see the potential for special event rooms being added (and removed when done) with a strict set of rules that must be accepted, active mods for the event, and a set start and stop time for an event. Maybe even a discord role that would have to be added once rules for voice are accepted similar to opting in/out of CE. But even this scenario could be complicated to manage and moderate fairly for both users and staff. Of course there is always the ability to spin up personal / private discords for voice chats but that are not manage by the site staff as is done already today.