I'm using your post as an opportunity to ask this.
What do you or any others want to see beyond the linear design? The original game was quite linear even though you had a sense of traversing the world, visiting towns out of order, find the odd thing in the environment. But it wasn't designed for you to take off and explore, it was designed to focus on going from one scenario to the next. Given the amount of game they still have to get through, expanding its design and scenarios plus all the additions they've made, I can't see how this will ever not be a linear design.
Is the linear design the issue, or is it that it felt like you were following a path to much? How would you want to see this changed? Or do you want a open world to run around in doing side quests, riding chocobos, monster hunting?
I personally think its going to stay with a linear design and I see no reason to have a massive open world. Maybe a environment you run through between towns with some monsters and branching paths.
I also don't get the issue with linear paths. I think its more of an issue that ppl don't like to see that's there's just one path. That people like the illusion of a bigger world even though you only need 1 path to go where you're going. The corridors in the game really only act as a space to feel like there's space between the two points you need to go. What do people want to do in all that space that couldn't walk around in?
I'm curious to know what it is exactly that ppl want instead, since its usually a negative point ppl make. Honestly an open world like Witcher, assassins creed or Dragon Age doesn't interest me. those games had me bored out of my mind with all the pointless spaces I could walk and all the repetitive quests I could take. However, I understand some really enjoy that aspect of those games.
So what kind of improvements on the linear problem are people hoping for in the next few games?
Linearity in story progression is fine and I don't think they need to try to be something else there. I said linearity has drawbacks but it has strengths that much better fit the game and between linear and exploration I would want FFVII to choose the former every time. I haven't finished the game yet (ch.17) so I can't really comment on the story at all, but as far as gameplay goes, even not having access to hard mode I have thought of things that they should keep doing and things they can improve upon.
As far as linearity in gameplay is concerned, they can definitely make improvements in their zone design. Original VII was very linear but the zone designs were varied enough that some exploration was needed. Obviously that can't translate at all since VII was random encounters, but SE already did something in XII that can translate very well to here. Zones with more interesting locales would have been hard in Midgar which is why I said while the linearity has drawbacks I think it's still the right decision, intentionally or unintentionally, for zones in Midgar to be very linear. Outside of it, I hope they try to do be a little more bold in zone design. XII isn't the most amazing in most instances either, but if future games can just try to approach that level I think that would go a long way. Being able to go to something you can see in the distance occasionally feels fantastic for world building. I think narrative world building they have it down pretty well and just need to polish a little, and gameplay world building as it currently is works for Midgar. However I think it would be a little lacking once you leave it.
What I really want to see is for them to think about tackling a potential problem that will happen in future games, as a result of increased party size. In the original it's basically choose your favorite three since there is very little difference between the base design of the characters. Remake has proved that they can create very unique characters gameplay wise, and in this game with only 4 characters, the amount of content vs available tools matched up pretty well. However, assuming future games will still have about the same amount of content, once you more than double the party, members will go heavily underutilized or not used at all. I think if the quality of each character ends up being up to par with current, that would be a shame that you won't be able to use them sufficiently even if you make the argument that it could encourage replay with a different main team.
The good news is that they have done something with active/sub in XII already so it's possible that they may consider that, but XII doesn't fit that well here since XII's combat system is completely different, a party of 9 is much larger than 6, and also because there is no aggro control in remake at the moment to dictate drawbacks that was present in XII. With that said, I hope they would look at Tales of Berseria's combat system for active/sub swap system, which I feel very strongly about as the best party swap system I've seen. If that one is implemented, you can field 3 active and 2 sub that can be swapped in (parameters, effects, conditions, and drawbacks can all be ironed out pretty easily with ATB being the basis of the combat system), which means that 5 out of 9 would be participating at any given time. An increase from fielding 33% of the party to over 50% would go a long way in providing play time for the entire party. This is something that I really hope might happen (but I know it's very unlikely), and what I was really going at when making the "more ambitious" comment.