Relay DHCPv6 assignments to outside DNS?

Hi, my apologies if I am not using the correct terminology in my question.

With the advent of IPv6 we know that hosts within our private networks can have globally accessible IP addresses. But what about communicating the DHCPv6 names up to an outer DNS service?

For example, if I own fancyname.com and my router DHCPv6 assigns an IPv6 address to local machine "node1," can I have it "tell" the rest of the DNS world that "node1.fancyname.com" resolves to the appropriate global IPv6 address?

That way people outside of my private network can access private machine node1 (with appropriate firewall rules) using the name "node1.fancyname.com"

Unless you have a static IPv6 prefix, this would (still-) be a task for ddns, either running a ddns client on each server individually or using a ddns provider that allows updating the prefix (and then does bulk changes for all registered suffixes).