IM metadata hasn’t been leaked to network operators ever since the wide adoption of HTTPS.
Discussion
Sir routers can see what IPs you are visiting, regardless of Https, so unless you are using Tor you are leaking metadata, even a VPN is just changing who you are leaking to.
If you make VoIP chat using webrtc you are leaking your IP to your contact, even in Signal, hell, you are leaking your IP to signal server all the time, it is all tradeoffs.
There is no such thing as perfect privacy.