Is this you saying or an article? Because i'm afraid to inform but an open world Pokémon is very unlikely.

The main series has a rigidity that is very much intentional. That is the reason why the series is so slow to make technical leaps. They are too afraid to lose the special sauce that makes it sucessful.

A game where the overworld has zero impact on the combat? Why people want to make things unnecessarily complicated or expensive.

This right here.

Pokemon is the only thing that keeps Gamefreak going, and if they mess it up it will be the end of them.

The overworld has zero impact on like 90% of open world games. Does the overworld impact Xenoblade's combat? No. Is Xenoblade's overworld the biggest reason why it's regarded as the best JRPG of the last generation? Absolutely.

It's very necessarily complicated and expensive. 

Game Freak are terrible devs. They couldn't make an engine that stays at at least 30 fps, in fact, it often drops to the 10s, and that's without 3D. That's why I just can't play Gen 6, it's unbearable for me, especially after experiencing the smooth as heck Gen 5. Now, this could all be the result of them switching to a new console, right? While I understand that, I also understand that Pokemon X and Y had the BIGGEST Dev team of any Nintendo game EVER! That's bigger than even the upcoming HD, MASSIVE, Zelda U. Moving to a new system isn't the problem here. I can't believe that with all the money they've earned, Nintendo never cared to refine the team like they do with other studios...

(On a completely unrelated note, that post was my first VGC post using my new phone! I just love this massive keyboard!)

Gamefreak are incompetent developers in a technical stance, no way will they even be able to make a full open world Pokemon game anytime soon. Unless they ask Monolith Soft nicely to make the world for them....

Well I'll just point out, the team bloat is likely due to the number of pokemon that must be modeled AND animated, which are time consuming tasks.  You can't read too much into the numbers; it's not that simple. 

GameFreak doesn't need an excuse to do what they do because they have people like you who buy their games no matter what.

I agree but I think GameFreak should continue to make the top-down games as well. The top-down games are still be good enough for most fans and will be quicker to develop  than a massive 3D game. These massive Pokemon games (let's call them Pokemon 3D) you're imagining will probably appear once per generation and have huge development costs. They also won't make as much profit if they end up selling as much as the top-down series.  If Nintendo decides that the first Pokemon 3D game will only have Kanto Pokemon, and only Johto and Kanto Pokemon for the second (and so on for Gen III to infinity), than they have even more reason to continue their top-down games if only because those have more Pokemon. However, I think these Pokemon 3D games are better suited for home consoles to further protect each series sales. 

In other words, treat Pokemon like Mario. The top-down Pokemon games will be like the New Super Mario Bros. games and the Pokemon 3D games will be like the 3D Mario games. If Nintendo has to expand or hire a new Pokemon developer team than do it! In the end, they will have another profitable series that fans will enjoy.