Well, that IS the part where Noctis throws his sword at an airship and zero-shifts to it, no surprise that his allies would be far away, especially if it's during the part where Leviathan starts to go craycray and throw shit around.
Also, I do think that's the whole world map (perhaps not the whole world of XV, maybe just a part of it like how Matsuno likes to do things). I wouldn't be too worried if it looks small, since I'd guess that the "main continent" in the middle is absolutely huge and the rest are still big enough that they'll take a considerable amount of time to go explore. If it was this way, I could actually believe that you could have an airship and a completely seamless world, just one where (at some point) the airship would automatically do an 180 degrees, so you can't go around the world like you could in old FF games.