In Final Fantasy XI the name of the Blue Mages were "The Immortals" and they were captained by a man named Raubahn. Gee wonder where that sounds familiar. The Immortal Flames in Ul'Dah is run by Raubahn who just so happens to also be an Ala Mhigan, not to mention that Ul'Dah is rather notorious for it's Ala Mhigan refugee population. I don't know, some people might brush that off, but I think it's just too much of a coincidence.

The other thing that makes me think BLU would just make more sense, is why release Samurai during an expansion about Ala Mhigo? Blue Mage follows the aesthetic much more than Samurai does if we want to make some comparisons to how they were in XI, and I think Samurai deserves a bit more, like being released in an expansion when traveling to Doma.

I also think BLU would make for a better tank than SAM, I am really hoping SAM won't be a tank but ehhh that's a person bias lol.

Long story short, could be SAM which is what most people thing, but in reality I think BLU would make more sense for this expansion at least.