"...But only if the surviving finished material doesn't already qualify as HD.
I mean, it does exist in a variety of LD formats, including VHS tapes on a shelf right next to me."
All that had been previously available on consumer video (VHS, Laserdisc or DVD) is only standard definition or 480 horizontal lines of resolution compared to Full HD's 1080 lines. None of that qualifies for HD, as the original masters are equally only available in 480i SD.
From DS9's third season on, improvements in professional video technology yielded a better picture quality but - again - only in SD.