This seems like a distinction without a difference. If you used a paid service offering Mumble servers that used some custom software that allowed them to offer multiple ... "servers" on different ports/IP addresses from a single daemon, would you really care?

Focusing on the fact that it's not really a "server" because they aren't running as separate processes seems like utterly silly pedantry, and we probably don't even know if that's actually true regarding Discord or not.