Op is taking about a standard definition release on blue ray, not the full upscale job the article is talking about. An SD re-release onto a larger medium is probably the best we can expect to get, but I’m doubtful even that will happen when looking at studios behavior
I’ve had mostly good luck with lower end NUCs. I say mostly because of 3, one died a hard and abrupt death after 2 years; but the other 2 have been fine going on 2 years now. The only problem with NUCs in general is they tend to be over priced. If you can find them on sale they are totally worth it. As others have pointed out, you should have a plan for more storage. Personally I’ve found a good usb hub and some external disks work great for what I do. As to why I like them: 1) form factor, low profile cube, 2) they happily run headless, 3) hardware seems to be of decent quality (ignoring my i3 box that never turned back on after a reboot), 4) most models have enough I/O to fit your needs.
Yeah, not sure on audio quality. To my ears DVD audio is already in the realm of diminishing returns unless the mastering was done very poorly. No clue if they were doing 5.1 or any sort of multi channel on the DVD releases either.
The better quality because of more room for higher bitrate makes sense assuming they still have the final cuts pre-dvd-compression laying around. This could get you some crisper, less artifacty output.
But this is also just speculation on my part. I’ve never checked out one of these sd-bluray-re-releases myself.