With ipv6 there are the privacy extensions[1] for SLAAC which will assign your computer a new v6 address from your network prefix in a regular interval.

This is enabled by default on windows, osx and some linux systems.

But I do wonder whether webrtc can find your other v6 addresses, a host often has more than one.

[1] https://tools.ietf.org/html/rfc4941