I just really hope the game doesn't feel rushed and lacking in terms of story/world/content due its short development time.
Is the development time really that short? Three years was about the development time of Xenoblade also, and that was with fewer resources available. The story was better (as of now) than XBC:X with its much longer development time. Takahashi probably writes these stories in a few months and then it is all implementation from there. The world sounds very interesting, with multiple Titans, although I am with you in hoping that each Titan is packed with quality content.