If people who want the 2004 transfers in HD already have them thanks to the tv airings, that's good for us. It means fewer people will buy the blu-rays unless Lucas puts some effort and all the versions on them.
To make a blu-ray, they should make a new transfer. A HD print made 5 years ago for dvd and tv is not as good as HD captured for blu-ray video. That would be extremely lazy (though not by LFL standards anymore) to just use the 2004 master and not fix anything again for the blu-ray.