I doubt Hoenn will get a sequel because Gen 3 was not designed for sequels. In B/W, we were only told about Reshiram and Zekrom, while Kyurem's story was saved for the sequels. Rayquaza's story was told in the 3rd version of Gen 3, so why would they go with sequels if the Groudon vs. Kyogre battle has already happened? It would make little sense to just have those events happen again when the intent was to tell the whole story back on the GBA. So if Hoenn appears in another game, I feel it would be plain remakes. Gen 5 was made to be finished with sequels, even though that wasn't their original plan.