Comment by conradev

One thing I realized with this is that there are multiple levels of metadata privacy:

1. Messaging provider cannot see which accounts message each other

2. ISP cannot see which IP addresses message each other

Using Tor here gets you both 1 and 2, but at the cost of latency: it is something like 6 hops to rendezvous with a hidden service. WebRTC (assuming Tor as a TURN fallback) would be a lot faster, but would not include 2.