I have the same problem.
I’ve reinstalled the packages after “rpm-ostree reset”.
sudo rpm-ostree reset
sudo rpm-ostree install \
https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-rawhide.noarch.rpm \
https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-rawhide.noarch.rpm
sudo rpm-ostree install <RPMS>
I have not found any problems with the Fedora silverblue rawhide package update.
But
In my case, the same problem when installing the kmod-nvidia package.
rpm-ostree install kmod-nvidia
...
error: Unrecognized archive format
After “rpm-ostree reset”, I was able to solve the problem.
I’m sorry I did not have good English.