If you think about how they are pretty much using WoW as a base example of how they generally want to run this MMORPG because of it's (WoW) success. Also considering Yoshida himself was a WoW player. Then I would think that like WoW, you'd have to go through a majority of the older main scenario if not the entire thing, before you get to the point where story-wise things make sense as to why you can go to Ishgard as well as the new areas.

From my personal experience, I played WoW for maybe about 3 months after the Cataclysm expansion was out, finally giving in and trying it with some friends of mine. I started at the lower level and the main story pretty much guided me along all the way through the various past expansion stories to some degree. (There were some areas that were blocked off from what I was told since they weren't relevant to the current world story anymore) Also there were many normal quests that were just side-stepped since experience was boosted from other quests. Those old quests might have held some minor back stories and stuff for all I know, but I didn't do them or even have to. Though the main story still seemed to flow together as I leveled up, eventually hitting the then level cap of 80 and completely finishing off what was available of the main story. (At that point, they hadn't even added in the fight against um... w/e that dragon's name was). But after I finished what was available of the main story, though I found that part actually kind of interesting, there wasn't anything else to hold my attention and the game got rather boring pretty quickly. Couple that in with my friends having stopped playing and I was done with the game.

Point is, I still experienced the older storylines and had to do quests to progress through the older content. I didn't just zoom straight to Cataclysm level content.

Though from what I understand the newest WoW expansion actually gave people who bought it (or was it just a preorder thing?) a free max level character, or near max level character. Personally I think that's the dumbest gimmick I've ever seen to try to entice a person to buy a game. "Buy our game! You don't even have to play it, just buy it!"

I hope they don't do anything like that with FFXIV. Players should experience the story from the beginning and catch up to the expansion's story. This is a Final Fantasy for crying out loud. Story is the main part of the game. If you don't want to see the story at all, imo you shouldn't be playing a game with one. People like that should just go play a MOBA or something, they don't seem to have stories from what I can tell. (I don't play them though, so just speaking as someone who has kinda sorta watched friends play them)