It’s similar for Red Hat. CoreOS added Notory support (Golang implementation of TUF spec) to Quay (container registry) for image signing based on the design from Docker Inc… Red Hat acquired CoreOS shortly before Red Hat was acquired by IBM. I’m not familiar with the details of Notary in Quay and there isn’t much documentation on the topic. The Quay registry seems to use an external TUF service to do the work.
Apparently there was some research to improve yum/dnf (package manager) based on ideas from TUF spec, too. The DNF specs don’t mention TUF. Fedora and RHEL rely on GPG signatures and hash files for packaging.