Earlier quoted context omitted.
Huh, is that true? If you push a new version of a tag, Github will ignore it? Or if you 'git fetch', git does not update tags? I would be pretty surprised at either of those.
It's the second one
Github shows the updated tag.
git pull --tags shows:
! [rejected] -> (would clobber existing tag)
git pull --tags --force updates the tag.