Did I make a mistake buying a New 3ds Xl?

Considering the latest generation (Sun / Moon as the 7th Generation) was released in Nov., 2016... the next generational release most likely won't be roughly 2019 & all other generations (with updated re-releases) are accessible on the 3DS (w/ DS backwards compatibility & 3DS VC for 1st Generation)... your purchase of the New 3DS XL for just Pokémon is probably OK as a result, although the Pokémon series tries to release for the wide array of systems... so getting a 2DS or the original 3DS would work as well.

If you're planning to play other games besides the Pokémon series, you can easily justify the cost of your console purchase.

imo yes but it can also be a no. yes why? pokemon sun and moon is comming out for the switch next month not sure about the game but the console is i can only assume the game will be as well. no because so many people invested in the 3ds that they will likely market some huge games like pokemon for the older versions. of course there will be exclusives for the switch as well like the new zelda game. if you can cough up money for the switch later down the road then it's up to you.

you can always return the game and ds IF you did not open them this includes packaging meaning even the plastic wrap around the game and or console if you did then you voided the return as it is deemed used. other then that i don't think it was a waste of money in the sense that there are a lot of ds games that are good and pokemon sun and moon doesn't have very great graphics at all

It depends on if you plan on going back and playing any of the 3DS or DS games dating back to 2004 (over 12 years).

There are plenty of good games out there that you can pick up and play.

If you pick up enough of them, it will make it worth your time.

If you only bought it for the new Pokemon games (not including Sun/Moon which released about 3 months ago), then yeah. There likely will not be a new Pokemon game for the 3DS.

We don't know if the next one is for the Switch or not as it has not been announced, but that's the working theory.

I doubt there will be a Pokemon game that is "New 3DS-only" since there are so many kids out there that have 2DSs and original 3DSs. They won't make a Pokemon game that limits their player base so drastically.