Kinda.
Sometimes, I wonder if they would, say, use Wyld-shaping technique or its equivalent in order to create an entire new Creation, you know?
Or maybe use Clarity 10 alchemical exalts, and use them as island of stability within the Chaos of the Deep Wyld.
And then there's the question of social structure. With abundant resources. Or at last the wyld to get more, resources are likely more than enough for the autochthonians. What does this mean? That means that the discipline and regimented lifestyle would probably not appear here.
What I'm wondering is the interactions between the races. The mortals, dragonblooded, jadeborn, and alchemicals.
Alchemicals are easy. Probably the same as canon. Jadeborn? Probably serves in the castes. Maybe as workers and crafters. the mortals? As the most numerous, probably all walks of life.
And then there's the Dragonblooded. What role would they be in? Would they be leaders, due to their exaltation? Or would they be champions of the people. One must look at the different themes for each exalt. Dragonblooded are teamwork, family, royal bloodlines, and elements. Alchemicals are modularity, champions of mortals, and products of industry of a society.
I do very much like the idea of high-Essence Alchemicals going on to form "satellite cities" or "colony ships" that travel alongside Autochthon's world-body and serve all manner of purposes - separated research facilities that can look into ideas and technologies too dangerous to be attempted on the Great Maker himself, harvesters that gather up food for the ailing Primordial, processing plants that refine wyld-stuff into highly specialized items and materials to then be sold on to the people of Autochthonia, halfway independent city-states for those whose beliefs differ widely from the Autochthonian standard, etc.
If we use
@Dif's ideas for the Void, there could even be a handful of city-ship Alchemicals who've embraced the Great Maker's darker aspect and seek to mimic his own passage through the Outer Chaos, forging their own destinies free of any other's design... or a seldom-spoken-of convoy of younger, smaller Alchemicals which house arms dealers, makers of mechanical enhancements, and other things held heretical by the Eight Nations, kept alive by a steady flow of clandestine visitors who value efficacy over government approval.
As for a new Creation... I could see a collective of very, very old Alchemicals deciding to try and "settle" part of the Wyld for their own purposes (perhaps with the aid of similarly-venerable Dragonbloods, to help establish equivalents to the Elemental Poles?) and bringing along a great host of mortals, Mountain Folk, and other settlers, with Autochthon himself pitching in to help shore up their defenses against raksha and otherwise smooth the way. It would probably look rather more like a plus-sized version of the aforementioned "colony ships" than Creation, however.
Race relations would be both aided and hampered by the greater freedoms in this AU. On the one hand, Autochthonia isn't completely closed off anymore, so there's more potential for people to go their own way - and the Great Maker himself is presumably awake, so he'd be able to step in if things started getting out of hand. On the other hand, the resource drought helped force cooperation and a minimal level of civility between the Eight Nations in canon Autochthonia, whereas this shard takes place in an infinite sea of wyld-stuff waiting to be shaped, and the "colony-ships" further open up potential social dynamics.
Cue ramble:
The Mountain Folk are Autochthon's chosen people - and with their creator on hand to help solve their issues with reproduction (whether by resurrecting the People of Adamant or finding some other solution), the Jadeborn would have more the air of a great elder race returning than the last heirs to a lost people. Likewise, they're far better-suited to surviving Autochthonian conditions than mortals, or even Dragonbloods, reducing the odds of land struggles between them and other races since they can just build their cities in places where the other races couldn't survive.
I'd see the upper castes (whether Adamant-born or something new) becoming advisors for young Alchemicals and the mortal nations in general, using their superior crafting abilities, storehouses of First Age wisdom, and connection to the Great Maker himself as a way to firmly establish themselves as beings to be respected and listened to. At their best, they help the Alchemicals grow into their role as champions of the people; at their worst, they alienate them, bludgeoning their charges over the head with ancient history and implied superiority until the Exalt can't take any more of it and cuts ties, leaving less arrogant Mountain Folk to pick up the slack and prevent a possible sociopolitical incident.
The lower castes, the ones fashioned as workers and tenders of machinery, get on well with the Autochthonian mortals, for the most part. The largest of their kind act almost as sapient construction equipment, working alongside mortal repair crews who can act more gracefully & on a smaller scale than their massive, powerful frames; meanwhile, tiny Jadeborn no taller than a man's knee range the outskirts of mortal outposts for signs of trouble, and crawl inside of massive machines to perform repairs on the internal components - often dependent on occasional help from mortal Autochthonians to fill orders for replacement parts, or deal with obstructions too heavy for their insectile limbs* to shift.
Dragonbloods serve different roles in different Nations - most often, as troubleshooters and middlemen who fill the gaps where the other power groups fall short. An Earth Aspect (or Metal Aspect, whichever) craftsman might not be as versatile as an Alchemical or as peerlessly skilled as a Jadeborn artisan, but she can do basic repairs and manage existing infrastructure just fine while the latter two are busy with other affairs - and more importantly, the Terrestrials are a more numerous & easily-renewed resource than the Alchemicals or the Mountain Folk. Commoners might mob an Alchemical with requests when once comes to their district, but the other 90% of the time, those problems get handled by the Terrestrial Exalted. They're the second pillar Autochthonia survives on - not as unappreciated as the worker-caste Jadeborn, perhaps, but definitely less powerful on a national stage. The Dragonbloods wield power on a local level, the mayors and sheriffs to an Alchemical's Chief of Police.
This is getting a little lengthy, so I'll cut it here, but remind me this afternoon and I'll try to sum up my ideas on the other big thing in this setting - raksha.
* By the way, I'm using @EarthScorpion's model of Mountain Folk, where individuals are given shapes that pertain to their intended function. A Jadeborn meant to act as liaison to one of the Eight Nations is going to be fairly humanoid, but a maintenance drone could easily resemble a cross between a sci-fi repair drone (arms with tools on the ends, etc.) and an insect.