If Toei was willing to do so, they would have done it a decade ago when everything else was getting Bluray remasters. The fact that it's 2021 and we still don't have a true HD Sailor Moon (or Even Dragon Ball Z) bluray says that we're never getting it.
One of the problems here is they got into it late since they didn't start putting out TV Blu-ray sets until Galaxy Express 999's upscale in 2014 while everything else before that were a couple of movies and OVAs.....starting ironically enough with the Galaxy Express 999 movies in 2009 (which while not upscales, were infamous for the heavy DNR that was applied to them).
Another problem that I have noticed, with the exception of the original Devilman, the only shows they seem to have no issue giving proper remasters to are those that used 35mm film, this was why Mazinger Z (1972) and the original Dragon Quest Dai (1991) got better treatment.
Since DBZ was brought up, they did put out the movies a few years back ("corrections" and all) but with how they have handled their other 16mm shows lately (80s GeGeGe no Kitaro, Fist of the North Star, Goldfish Warning, etc), I can only see all 3 Dragon Ball shows get SD Blu-ray sets at this point which would kinda suck for the 8 Freeza episodes that were done on 35mm.