None of the leakers have revealed that yet, but stay tuned!
You know I think you are onto something here.
Also, I do admit there's loads of Hoenn shout-outs I admit:
- An NPC saying this about the Hoenn region: "You will see it in due time"
- The mention of Hoenn and the anniversaries called Ruby and Sapphire
- The Hex Maniac trainer class being present, for the first time since 3rd Gen
- Yveltal and Xerneas being red and blue in color respectively, while having abilities with similar effects, sorta like Groudon/Kyogre
- The main characters Serena and Calem also having their default clothing that's primarily red and blue respectively
- Zygarde being a Dragon-type, and having a serpentine-like body, similar to Rayquaza
- Zygarde's ability cancels out Xerneas/Yveltal's abilities, much like how Rayquaza's does a similar thing to Groudon/Kyogre's abilities
- The fact the 7th Kalos Gym is a Psychic-type Gym, much like how Hoenn's 7th Gym was also Psychic-type
- The player is not originally from Kalos, much like how the player in 3rd Gen was not originally from Hoenn