Yum (and I seem to recall up2date) have had certificates revoked before (due to compromises on the upstream packaging system) requiring everybody to re-import a good certificate before updates will work again.
Now, system updates are a different beast than tying your development process into Magic Hosted Things In Internetland, but certificates on things have been changed before and they will be changed again. Just have to keep aware of how your systems work and what they depend on, which goes against modern "javascript with a double large lack of knowledge" development.
Now, system updates are a different beast than tying your development process into Magic Hosted Things In Internetland, but certificates on things have been changed before and they will be changed again. Just have to keep aware of how your systems work and what they depend on, which goes against modern "javascript with a double large lack of knowledge" development.