LOL. As you mention it - why Gamefreak never had this idea. They would be so rich by now.

Yes, and you don't have to buy both to get a full experience. The difference is just to encourage trading, a huge huge staple of the franchise from the very beginning. They're not going to get rid of it. 

The thing is, The Switch version might allow you to make multiple accounts with 1 game card. While the 3DS you couldn't.

One game for docked, and one for undocked play.
Easy money.

Yes they will. Because the two version trading dynamic simply works. I am 100% sure they will purely for the social aspect of it.

Yes - and a season pass.

Probably, but it could be worse, such as the "third" version that you'll have to pay another full $60 for even if you own the original. It's essentially a "GOTY" version except they don't offer any of the content as DLC for owners of the original.

Why bother making and shipping some hardware, when somekind of DLC/season pass can be sold throught their payed online service.

Yeah I always cringe when I read that. The games have had online trading since...like...2005? Even if you don’t have IRL friends to trade with, you haven’t needed both games to get all the content in over a decade.

I suppose if you’re hardcore enough that you need both games to see all the minor dialogue swapping you’ll want both, but then you probably also want to get every alternate box art or special edition of any game, and that’s certainly not unique to Pokémon.

Anyways on-topic, I’d be very surprised if they didn’t release two versions. It’s basically money on the table.

It must also increase sales though, or else they wouldn't do it.