FinalFE +1

When uninstalling a package previously installed with PackageKit using dnf, no unused dependencies are found and removed. This was fixed in the latest dnf/libdnf update, however the fix is not retroactive as the dependencies previously installed by PackageKit are already committed as userinstalled to the database. Because of this, it would be a good idea to push this fix into F39 before the Final release.

I would agree on the basis that there can be "damage" irreversable by a system update, and it's not unthinkable that someone would install a package with PackageKit before doing updates, for example consider the following:
You just installed Fedora, open a terminal and run neofetch as the cool kids do. It is not provided by the base image so command_not_found_handle is triggered and PackageKit proposes to install it, bringing in a bunch of dependencies.

However dnf is probably one of the packages you absolutely don't want to break a freeze for unless strictly necessary.

Good point. However, I still think that this update should be fairly safe considering the changes it brings.

Also, there is one more important change the new build brings:
"BZ#2221907 dnf5 is not marked as protected, removal leaves system more or less bricked"

FinalFE +1

okay, based on that justification I can be:
FinalFE +1

Particularly considering we've already got a fix:
FinalFE +1

Release F39 is no longer tracked by BlockerBugs, closing this ticket.