Geomancer

[ArcaneCarbuncle]

Well there is history of a class and then there is a history they have established for a class in game.

And they obviously should use the history they already created, I just don't think they should limit themselves to it.
I'd simply prefer for them to come up with a unique concept, both for gameplay and visually, and adjust the lore as necessary. They can do so and have done so before.
For example, while the lore we've got up until now says GEO usually uses Water/Earth/Wind, that might be simply because these elements tend to be the most accessible, but a skilled GEO in the right environment can draw on any element of their choosing. Its just not common knowledge due to the relative rarity of volcanic/frozen/thunderous environments. Fits well enough with GEOs classic theme of using the Environment and explains why we've never seen a GEO use Ice/Fire/Thunder before while leaving the door open for them to be part of the skillset.

The debate of the Ast quests will also always be here I feel like, because it is so split down the middle on how people interpreted those quest chains. Wasn't all that was said was Levava saying how they were similar due to drawing power from a star/stars and that their casting complemented eachother? Also that they could learn a lot about their own schools of magic from studying the other. I know that Swallow's Compass was released in 4.3 a year after the Stormblood launch with the Ast class quests and nothing about that dungeon was very astro-y, granted this is also just opinion.

Never said AST and GEO were the same thing, lorewise they were always presented as seperate entities. It just always seemed to me like SE originally planned to roll some concepts from GEO into AST rather then make GEO a standalone job, what with Leveva musing about fusing the schools and all.
At least that's always been my theory; though it seems they've abandoned that idea - probably due to player feedback or popular demand for standalone GEO or shift in Healer and/or overall job design or any combination of reasons.

I know at the time there was a big debate of people saying that this was SE shifting Ast to a more Geomancer centered style of play, but Ast have never received or even had anything Geomancer related in their kit.

Earthly Star says hi - kind of. Ground targeted effects as an engine for GEOs Terrain-command were a popular suggestion back then (and still are to an extend).
It's not much of a stretch to believe Earthly Star to be early experimentation for that concept.