I don’t know if it would make sense for them to ever make Dark Souls 4 since Elden Ring is the more popular franchise and they’re probably going to stick with open world going forward. But I think it would be pretty sweet if they made a remake of Dark Souls with an open world or something.
I could maybe see a return to Dark Souls at some point way in the future, more like a soft reboot or expanded reimagining of 1 to cash in on the name. I don’t think it’ll happen for a long time though, similar to the big gap between RE4 and its remake, or the upcoming MGS3. I also doubt Miyazaki would be the project leader since he prefers to try new things.
IMO part of the appeal of Souls games is piecing together the lore and background of the world, and the DS trilogy exhausted a lot of that. People want more of the same because it feels comfy and familiar, but the lore was designed to have gaps and there’s only so much they can add before it starts to feel like bloat. I’d prefer to see fresh experiences each time, but would love to see a return to the puzzle+trap level design of DeS/DS1 and more heavy, deliberate combat.