So at the end of Pokemon Sun and Moon you see a lot of things hinting in a bunch of different directions. So it made me wonder what you believe is most likely:

With Lillie and Lusamine heading to Kanto to become a trainer and help her mom, it could be hinted that we may get a Red and Blue sequel. On top of that there were many hints in the game pointing towards this possibility. This game would take place post-HG/SS which means we'd probably get some parts of Johto too, or perhaps only Mount Silver. But I'd imagine a lot has changed since we last saw Kanto. 

The third part of the legendary trio, Necrozma, could be hinting at a third version (Stars?) since its stats all but indicate it is not a complete legendary just like Kyurem and Zygarde. It will have another form. However, whether it goes the 3rd game route or B2/W2 route hasn't really surfaced. All we know is Necrozma WILL have another form due to its stats and ambiguous backstory.

Or will they pull a B2/W2 and show how much the island has modernized since we last saw it? 

Your a tad late to the party but yeah, Red and Blue 2 does seem like its quite possible at this point.
Im still expecting Stars first though before we get Red and Blue 2.

You also forgot the number of hints in the lab where Kukui's wife works has a ton of data on gen 4 Pokemon. Specifically Giratina and Palkia. Could hint towards going back to sinnoh or remakes alongside sun/moon.

I'm dying to see Kanto again. One of the best regions, and all my childhood memories contained in it.

I'm betting that some pokemon from other regions will evolve different forms in Kanto.

i think its very likely we will have another sequel story rather than a third, especially given how much more of a timeline Pokemon games are beginning to have.

Well not late, I just wanted to give people time to play it and wanted to 100% as much as possible XD

Yeah, Its interesting how they basically de-cannonized Emerald. So as it stands, Ruby/Sapphire/Emerald, Red/Blue/Green/Yellow, Gold/Silver/Crystal are part of the "other" timeline

I always thought a sequel of gen 1 was smart. All i kno is gamefreak will surprise us again. Gen5 started the non traditional game releases. We all thought grey and z was coming but nope :p

I think Stars will be a B2W2 situation. They can't really go back to retelling the same story anymore. Plus they already have the set up with trial captains literally being gym leaders, and there being vacancies all over All where gyms would be.

As for a Gen 1 sequel, as compelling as that would be, I honestly don't see it happening. I guess that could be there in place of a remake, but I think they'll just want to release the next generation on the Switch ASAP. If Stars comes out in 2017 and R2B2(G2) comes out in 2018, than that means that Gen 8 would come out in 2019 at the absolute earliest. More likely 2020, since that number just looks better and gives them more time.

I don't think they want that.