The videos are mentioned on Udiscover Music. No mention (yet) of a Blu-Ray/DVD, but I suppose it makes better marketing sense to dripfeed information (especially if it's likely to get lost in any imminent publicity surrounding new music....)
The 4K remasters look very promising; in some videos like Knowing Me Knowing You and The Winner Takes it All, it sort of looks like they went back to the negatives and premasters that were just digitised recently and recompiled them (obviously through a different fading, perhaps) as a new master. Some videos, they use finished prints and redid some scans or fixed something up.
There are some things that I find flawed here, recurring in some videos, luckily not much:
-Excessive noise reductions that it sucks the film grain out (oh boy. This might seem good or necessary but I just like my copy of a digitised film a bit rawer, haha!) -Deinterlacing shows a bit edge in Chiquitita; this is inevitable but it seems a bit too obvious when you take a bit of a closer look, but not obvious when it's not directly in front of you.
The dynamic range of the music videos recorded via film is somehow better, no doubt, but I kinda wish they were a bit consistent and fixed in terms of brightness; but I suppose the way they left it a tad brighter, would give people more ways to customize their settings on TV.
And the other fixes in the remasters are a bit of a labour of love and interesting that it's photogenic - forget photogenic, it's cinegenic!
Considering that these were made for broadcasting everywhere rather than being limited to a spectacle of theatrical vendors, and/or perhaps there was a deadline to get on with ABBA Voyage, I don't think it would be too much of a problem when viewing it from a reasonable distance at a comfy room; as long as it's viewable and not intrusive, I can live with it.
I did see a post a while back via ABBA The Museum on IG that some music videos were filmed in 16mm which kinda accounts for some of the flaws being that it's "lower quality" (is it?) - whatever workflow or masters they used to do this is beyond anyone's ken.
ABBA's timing of jumping on the 4K remaster bandwagon as other bands did is quite a stroke of luck, yet it coincided with preparing for a newer journey that seemed fitting.