Okay but Ishgard and ALL OF THE NEW CONTENT are explained early in ARR: "Ishgard left the alliance and shut its gates". They tell you that IMMEDIATELY into the Scion portion. They are explained as xenophobic. There's no room left in Eorzea for the new job guilds to be located; it makes total sense that they would come from a place adventurers had never been because we had never seen them before. And because they were starting these new jobs without a base class, it would make ZERO SENSE for a BRAND NEW PLAYER WITH NO UNDERSTANDING OF BATTLE MECHANICS to start at level 30. There is no more room in the pre 3.0 maps to add any new locations for us to visit, and they wouldn't be able to explain them easily lore wise either. EVERYTHING BEING LOCKED AWAY IN ISHGARD IS EXPLAINED EARLY ON BY LORE. When you visit Coerthas early on, you see astrologians mentioned.