I was under the impression DNF5 was being held of until F39?

https://bodhi.fedoraproject.org/updates/FEDORA-2023-b3c645d401

"dnf5" is a separate package from "dnf" (version 4 in F38). It's already in stable repos, and you can install it and experiment with it, if you wish. "dnf" is going to stay at version 4 in F38, don't worry.