See perhaps "Reaction of IPv6 Stateless Address Autoconfiguration (SLAAC) to Flash-Renumbering Events":

* https://datatracker.ietf.org/doc/html/rfc8978

And "Improving the Reaction of Customer Edge Routers to IPv6 Renumbering Events":

* https://datatracker.ietf.org/doc/html/rfc9096

Also maybe "IPv6 Multihoming without Network Address Translation":

* https://datatracker.ietf.org/doc/html/rfc7157

Lots of good presentation at the IETF meeting for the 6man and 6ops WGs.