Yes, mee too.
I was surprised to see that the first rpm-ostree upgrade has generated many errors and failed on the next day of a fresh F39 Kinoite installation.
However, the update showed up in Discover, in the Operating system section.
I tried applying it via GUI, it was successfully downloaded, but again failed in Discover.
Well, after several reboots (and minor command line installs), the update again showed up in Discover.
I tried to start it again just for a laugh, but it did download and install!
After subsequent reboot, it now shows as the “currently booted version” in Discover, while the previous is now the “Fallback one”.
Apart from that the system is very stable, and the CPU temperatures on the Linux 6.3 kernel are at their new lows, never seen in Windows, and better than in F37 Workstation.
P.s. I’ve opened Discover just to look up information to write this post, and it gave me this popup message: rpm-ostree transaction failed with: error: While pulling fedora/rawhide/x86_64/kinoite: While fetching https://ostree.fedoraproject.org/summary.sig:  Error in the HTTP2 framing layer
Although I did not click anything, and have set updates to manual.