Conceptually there is potential.
From post-Elden Ring have more clout, so if they wanted to truly remake these from the ground up they would be able to fix some of the things that resulted from running out of time. Miyazaki would just make time now hif he wanted to, I'd imagine. They've earned the right to have a second chance, and wasting it would be a shame.
Miyazaki said in an interview he regrets Bed of Chaos, but as we all know Lost Izalith as a whole was unfinished.
There are also smaller things that needed to be data mined to be understood and could be tweaked to be more visible and useful, such as the Way of White circles that would appear in some areas and were supposed to enhance miracles (and have multiple tiers) but were never explained and had too small an area of effect.
If I were doing this and I were Miyazaki I'd also throw in an Easter egg invader of ninja flipping Havel or Giant Dad just for fun. Put it in NG+ only.
2 has the most potential for improvement. I actually installed it again recently, and between mods fixing some things and a mindset change of how to approach the game (e.g. intentional slowness) I enjoyed it much much more than I have in previous years. I was planning to do a full run and making a thread defending the game, but I got a bit bored after one DLC and couldn't choose a new weapon when Santier's Spear got old. Then I was reminded how good the other games are and realised it's still low on my ranking so it seemed a bit pointless.
List of basics to fix and stop 2 getting in its own way:
- Fix the sticks. Movement and camera on full analogue, no messed up dead zones
- Camera following closely when you move like ever other Souls game. This was more impactful than I thought it would be
- FOV. Every game benefits from pulling out but 2 needs it the most
- Durability. No matter the intent it's just an annoyance for most players because it's too extreme.
2 has SO much content (almost
too much), and it is criminal that more people don't get to enjoy it to its fullest. Despite the weirdness of the gameplay it really does make PVP far better than the other games.
3, naturally, has less glaring flaws than the other two and needs a remake less. I'm sure there are things that could use the improvements but I can't think of them. They could enhance the weapon arts and go full ER with it, but that might be unbalanced. They better not fix the tree jump at Firelink.
In all 3 there could be improvements when it comes to things like obscure questlines. Onionbro in 3 being hidden in a well you have no reason to go back to is bad, so that's an easily missed questline that has both an impact on a boss battle and a nice ending.
All games could also use easier offline farming for covenant items or some other tweak. There's too much good stuff locked away behind an ungodly amount of farming. Similarly, in 1 the Gravelord covenant only works on NG+ players and it's a bit rubbish as a result. I play with a mod to enable those enemies and it does add a nice layer of difficulty when you want it. I don't know how you'd stop ruining new players' experiences, though.