^ since ENT was mastered in HD CBS Home Video was going to release it as a HD home video product. They knew it in 2006 when they started TOS-R. At the time HD-DVD was in the plan for TOS. When the HD format war was over CBS made plans to release on blu-ray and do special features (Value Added Content VAC) and coincide with the release of TrekXI film.
At this point they have the work done for TOS, And a ready for encode ENT, and a expensive and time intensive TNG that is halfway done with season 4.
They were not going to spend the money on ENT to redo VFX when the master was in HD technically.
If they think ENT has a great future in syndication, download, a all-Star-Trek 4k channel, a 4k or 8k physical home video release they will pay to remaster in 4k or 8k (the first 3 seasons from 35mm film) in 10 years. Season 4 is locked at 1080p resolution (uprezzed in-camera from 1080x1440 - Sony HDWF-900 camera)
Some 35mm shot tv shows are doing it right now for 4k.