Hoo definitely D/P! I'm hoping as such, anyways. Logically, it's the next step, but D/P were my favorite games. Hikari is also my favorite character, so I'd love to see a redesign of her! I heard that in SuMo, it hinted at a D/P remake. SUPPOSEDLY. Little coincidences that people believe are hinted towards D/P, such as blue & pink backgrounds of battle challenges, Type:Null looking like Arceus, and something about one of the islands looking like a real island in Hawaii, where there are two landmarks called Diamond Heak and Pearl harbor I believe. Could all just be coincidences, but who knows Here's to hoping for remakes!
The thing with a third game is that I don't really know what they'd even call it in this series besides maybe Eclipse. There honestly hasn't been a third game in a while, not since before Black/White if I'm not mistaken, so Nintendo may have honestly just taken out the third games idea entirely. I also noticed there was no emerald remaster.
We could say third or fourth game, Black and White went to a direct sequel in B2/W2. Also I don't expect ORAS to get a sequel as Fire Red and Leaf Green didn't have a blue version with them so I didn't think any reboot would get a third game. Of anything maybe we will get a Sun and Moon sequel over a third game close to the original two like most third games are or maybe it will be a reboot game.
Given the pattern Sinnoh makes sense, but honestly I would prefer they not. I disliked a lot of Sinnoh, from bland enemies, boring towns and forgettable Pokémon to that stupid mountain and their reliance on bad HMs, I would much rather play remakes of any other region.