Not that it really matters all that much, but as someone who plays as much more immersion as I do "gameplay", I'm super bummed that Heavensward isn't looking to have a new starter area.
That's not to say that it NEEDS one or anything, simply that I feel like it could make the overall experience "flow" a little better. Assuming the new Jobs were accessible at level 1, have characters of those Jobs start off in a small Doman refugee-camp, somewhere on the outskirts of Mor Dhona, perhaps on the other side of the lake, playing home to lower-level monsters.
Of course, the timeline would be a little funky -- you'd have to meet Thancred and join the Scions while they're still in Horizon, thus begging the question "How are the Au Ra here?", but let's be honest, there are going to be plot-holes either way. Throwing another wrench into things, I might suggest introducing the Crystal Braves as a proper Grand Company, with the caveat that when you sign up for PvP, they enlist you alongside whichever nation is the least represented. As for Story Missions, once you hit level 15, they just send you back to Thanalan (since it's most convenient for tackling the Main Story quickly).
The main thing I like about this suggestion is, obviously, it gives you a little more immersion for starting a new Au Ra character. Yet also, it gives more incentive to have these new Jobs start at lvl 1, since you'd actually have a new location to carry them to level 15 (at which point, you can start spamming Guildhests anyways).
But hey, it is what it is.