I just want to say first off I don't think we'll get, or need, prequels, or a game where we play as an established character. Pokémon is a game about playing your own adventure, and it's kinda hard to imagine it's your own adventure when you're literally another character. Aspects such as the Original Dragon can be incorporated into post-game elements of a remake/sequel, which I'll get to in a bit.
Now onto remake/sequel possibilities. If they're going to remake BW and B2W2 but as one game each, I don't think they'll name them "[Something] Black" and "[Something] White" because that's just confusing. If anything they'd be named something like, just some random idea, "Pokémon Yin & Yang" and "Pokémon Yin & Yang 2" and then you can pick version differences within the game itself. It's just way too confusing to name one Black and the other White when one of them is actually B2W2. Either way, I think this is definitely feasible but I don't know if Game Freak would be willing to go through with it. By the way, all arguments made from here-on-out are going on the assumption/hope that by the time gen 5 remakes are due for an appearance, the hardware available allows for, essentially, two games on the same singular cartridge. Anyways, if Game Freak made one game to represent both BW and another to represent B2W2, but you picked your "version" within the game itself, it may deter people from buying "both versions." Not that it would stop people from getting the BW game and the B2W2 game but rather, some people buy both versions because they are in a very technical sense different games. But in this case "Pokémon Yin & Yang" has both Black and White in it, so if you "wanted both" you'd have to buy the actual same game twice. That does run the risk of a drop in sales. On the flipside, they could just remake each game separately. "Pokémon Super Black," "Super White," "Super Black 2," and "Super White 2" for generic naming purposes. But that ultimately results in four separate games worth of gen 5 remakes. While I wouldn't complain in the slightest and do think it's reasonable to expect, I'm still not sure if Game Freak would actually do it. This is just my pessimistic side speaking. Although, if this did happen, I can imagine the multitude of bundle opportunities: B+W steelbook combo, B2+W2 steelbook combo, B+B2 steelbook combo, W+W2 steelbook combo.
But why is it a problem if they don't want to remake the games separately? Because BW and B2W2 are different games and need to be handled as such. If Game Freak chooses to remake B+B2 and W+W2 on the same cartridge, there's only two possibilities I can think of: the games are, first and foremost, BW remakes, and B2W2 is delegated to a "Looker/Delta Episode"-esque post-game role; or both games are literally on the same cartridge.
Let's start with the first option. I really hate this option. B2W2 deserve to be their own full-fledged games and I can't imagine they'd work well at all as some minor post-game "episode." Unless these were massive post-game episodes where you go through and battle each Gym Leader, fight through the new Team Plasma, etc., I don't think any fan of gen 5 would like it. It wouldn't even really be "B2W2" at that point, because the story itself wouldn't work. You wouldn't be playing as the B2W2 protagonists, so a lot of the character interactions wouldn't have the same meaning (Marlon, Colress, Hugh, Cheren, Bianca, etc.). It would be easy enough to do, adding in some post-game areas to reflect the new places in B2W2 and add in a few NPC battles with new major characters such as Colress, Hugh, the new Gym Leaders, etc., but it wouldn't feel like B2W2 and I can't imagine fans of gen 5 will react to it very well. I know I wouldn't.
So then we reach the "both games are on the same cartridge" idea. This may pose some problems to begin with. Once the "B2W2" portion of the game starts, it's easy enough to add in the new areas and keep Route 10, so every location across the two games are accessible. But when would you get access to your BW Pokémon? How would you be able to switch between the BW/B2W2 protagonists and have it feel "right?" Because the BW protagonists are not in Unova at the time of B2W2 and that's something I don't think should change. These are important questions because with gen 5 having BW and B2W2 be separate games, you can go through all of B2W2 but still go back and play BW whenever you want to play as the previous protagonists (which is important to some people).
I think this idea could work, however, if they took an approach like this: you start up the game and play through BW. Once you beat BW and the credits roll, the next time you start up the game it begins "Two years later" and you get to play through B2W2. Once that's completed, a new post-game "episode" can open up (The Gray Episode???????) that takes place, well, after the events of B2W2. I don't know what the conflict would be but it could potentially involve the Original Dragon (since lots of fans would like to see it), and it could culminate with the BW protagonist returning to help. This would establish why they're back, giving the player a legitimate reason to be able to switch between protagonists at will (and have access to their Pokémon) once it's over, and since it would be an "all-new story" it would be okay that it hadn't happened in the original (also I personally would love to see something like that happen). It would also give players a way to experience BW and B2W2 in their entirety while also having something new to experience in the end as an added bonus. (Also: you get to have the "data transfer" from the original gen 5 without the need for two systems.)
I know I'm placing a lot of importance on the ability to "switch between protagonists" but it really is something that's big for fans of certain protagonists (imagine if gen 1 and 2 were on the same cartridge but then you could never get to play as Red again once you go to Johto), but it's also important because in gen 5 the protagonists themselves are important. Because of their stories, it doesn't make sense for Hilda/Hilbert to be playing through the events of B2W2, for instance.
This is honestly the best way I can see gen 5 remakes happening. It's rather ambitious, yes, but I think gen 5 deserve remakes that capture the storytelling strengths of their originals, and that really can only be achieved through these kinds of means: treating BW and B2W2 as separate entities and remaking them in their entirety. I would not actually be opposed to another set of sequels, but then you aren't remaking gen 5, you're adding to it. This is definitely not a bad thing but I love the idea of experiencing BW and B2W2 in full 3D with potentially amazing series additions by the time they come around (imagine experiencing Skyarrow Bridge not only in full 3D but with a controllable camera). I really wouldn't be against B3W3 if they were made well, but I would still like to see gen 5 revisited, and any "after story" could be included in the post-game if Game Freak felt it was necessary, so ultimately I'd prefer gen 5 remakes.
