You said, or made it look like you're saying, that XII set up little to no chance of revisiting old locations, chocobo exploration(...) etc. XII has both. You can literally backtrack the whole thing on foot, minus the Draklor Laboratories, the Leviathan and the Royal Palace. You can't really compare XII with X and XIII in terms of level design.
Also, there are several locations in XIII-2 from XIII. They're just really hard to spot because they look so different.
Lightning Returns though had... none?
I do see your point, just nit-picking your examples
Again, I said -
If they're making several separate titles, with locations set up similar to FFX, XII and XIII, that probably entails little to no chance of revisitting older locations, vehicle/chocobo exploration etc.
If they're making several separate titles is the qualifier for the entire sentence that follows. I'm not sure how I could have made it any clearer than that.
Also, XII is perfectly comparable to X and XIII in the context of what I was saying, in that although lay-outs and approach is different, the fundamental design principle of them is exactly the same.
That is to say - it's not an open world, and it does not feature an abstraction such as the world-map to convey traveling between locations.
Nit-picking my examples when my examples where not examples of games where you cannot back-track is not a nit-pick - it's just... I don't know, a misunderstanding?
All of those titles feature the possibility of back-tracking to earlier locations. I'm fully aware of this.
The point here is that, again, they are stand-alone titles, which FFVIIR will not be - It will literally be several stand-alone games according to the developers, and for that reason going for the same level design as these three earlier titles poses a problem.
Namely that for back-tracking to work between locations of the games, either all previously visited locations must be included in each new disk, or there must be some install feature which will allow each new titles to read the old map-files off of the console.
Because that's a lot of work, it's reasonable to assume that if they've gone for this kind of level design, then locations we visit in part 1, probably won't be feature in part 2 etc.
If however, we see glimpses of an open world, this essentially means that they've gone ahead and designed the world first - meaning that if they're going through all that effort, it's pretty clear that at some point we'll get to explore it fully with back-tracking an all.
Now, they could still do the non-open style of earlier games with the install HD solution, or putting all the locations on each disks, but that simply seems unlikely because it presents so much more work that you have to do if you've already opted for a much simpler world-structure to begin with.
In simple terms :
if they're playing it lazy with the world-structure, we shouldn't expect to see cross-installment exploration.
If they're going to full mile however, it would be madness of them not to implement it.