I don't get why "seamless" is a good thing in this case. The cool thing about old school JRPGs with a world map was that they created the illusion of being a big globe-spanning adventure. It's a good thing that Kalm and the Chocobo farm are presented in full 1:1 because that's where the interesting shit happens, whereas we don't need the same level of detail for every inch of grassland in-between.
Not to mention, the more "in-between" terrain they add, the more they're going to try to fill that area with stuff to do in order to justify it. Open-world game design usually sucks, and Square-Enix definitely sucks at it.
Guess we'll see how it turns out, but 99% chance they're just going to fill it with bullshit busywork.