Seems we have an answer on the 'lore' vs. 'new player friendly' NIN option ^^

[Felis]

0_o Curious George and the BLM trainers and the two Padjal kiddos are so very deeply connected to the lore?
Part of the point is that Ninjas don't even come from Eorzea in the first place.

The 2 Padjal kids are the younger sister and brother from Kan-E-Senna and part of the Gridania lore.

Besides, they're likely updating the intro main scenario quests lines (up to 15) which is why they mentioned you have to do at least up till then to get the Rogue quest, that way they can actually make logical sense of suddenly having these professions without having to do the main scenario through 2.3.

I don't know why they would need to update the lv1-15 storyquests. The devs could also simple put in a new quest for lv 10 that give you a password as a reward to enter the underworld of Limsa Lominsa (there are already some places in Limsa since 2.0 where a gate block the way while the area behind the gate is still passable on the map). The underworld exist since a long time in secret, according to the 2.2 story.

I think it would be like it is now:
Lv10 starter class quest - unlock the Armory
Lv15 story quest - allow you to travel to Limsa or from Limsa away

It worked since last year. No reason to change it now, even if Rogue is not available as a starter class.