I dont think that the hole was just somthing the programmers put in to use as a wall, cause the best thing to use for that is a wall its self. Why put a big hole there when they could put a wall... I myself think it is the place where the first lunar cry hit. i might have even read something like that in the tutorial. I dont have ff8 anymore but my memory is still fresh( I hope ) and if it was actually pupu's plane then that would really surprise me.