Predictions for 5.3?

[Archwizard]

-snip-

I love how I'm depicted as being "hard up for some Meracydia" when I already said I'm not counting Sharlayan out, while you're not even pretending to be balanced with the way you present information.
"They have sailing ships" is kind of moot when every non-landlocked nation in the world does, and several of your points like "highly political and love to debate, in many ways reflective of Amaurot" could all be wrapped together.
Several pieces of minutiae you list ("Archons! Thaliak! Allies from there!") don't even constitute anything substantial about the society itself. They're flavorful factoids.

I wouldn't be too concerned about the possibility of Meracydia vs Sharlayan, I'm just frustrated with the imbalanced and illogical arguments against either one.

What we know about Meracydia:

The Miqo'te are believed to have originated on Meracydia, before they were driven to Ilsabard by the Allagans and then came to Eorzea after the Age of Endless Frost.
There is a Meracydian horde of dragons born from Bahamut and Tiamat. Under Bahamut's leadership, the Meracydians were able to mount a significant resistance to the invading forces of Allag, who were considered even more advanced than any races living today; this may also tie to whatever unknown reason Xande was hellbent on conquering them. The Ascians later consorted with them to summon Bahamut as a primal after he fell against the Allagans, and to have said primal captured by the Allagans.
In response to the fall of Bahamut, the Meracydians turned to summoning primals for defense. Chief among them were the Warring Triad, summoned by: a race of tree-like beings; a race of centaurs; and "the diverse peoples of an ancient Meracydian nation united by the worship of Sophia". Sephirot's powers in particular were abused by the Allagans for much of the bio-engineering in Azys Lla, while the process of keeping the Primals in stasis prevented the Meracydians from re-summoning them.
Lanners are a large part of Meracydian mythology. The treelike race of Meracydia claims the lanners "bore the seeds of the World Tree" across the globe; the same World Tree is depicted by the Astrologian's Bole card.
The song Equilibrium also highlights the balance-based tenets of the Sophian faith (in which a maiden is encouraged to kill her abusive mother to "still her broken melody", and then herself for the crime of murder, essentially implying all crimes are equal).
Azys Lla is largely composed of trophies taken from Meracydia, possibly including the ruins dotting its outer quadrants. Of particular note is a Cathedral in the Gamma quadrant, which shares many symbols and patterns with the Sunken Temple of Qarn, itself said to predate the Belah'dians who eventually coopted it.
The Allagans under Xande employed Voidsent to ravage the Meracydian continent, who in turn created a self-replacing army of undead.
Between the Allagan attacks and the repeat summonings, the land is still heavily scarred and largely uninhabitable today, with scattered reclusive/violent tribes.
They have witch doctors who break from the reclusivity and continue to trade with Eorzea for potion ingredients.

And that's ignoring what may be left on Meracydia from the Allagan conflict, considering Allag made a number of great strides to biological engineering (chimeras), magic (Summoning), and technology (the prototypes for Ultima Weapon and activation of Omega) in direct response to the Meracydians. Considering how much of what the Allagans made seems to be built to last everywhere else on the planet, it is extremely probable the land still has a large number of roaming Voidsent, undead, chimeras and Allagan machines, and that the relatively recent destruction of the Warring Triad may have freed them to be resummoned by whatever factions are left on Meracydia.

... I would say that's plenty of an idea of what we could find there.