When I was looking at studios in Washington state on GameDevMap, it listed The Pokemon Company International (Bellevue, WA) as a "Developer" company. So does that mean the company actually hires people to work on Pokemon game titles? 

No.

From the description on their web site that took about 10 seconds to find, that company is "a subsidiary of The Pokémon Company in Japan, manages the property outside of Asia and is responsible for brand management, licensing, marketing, the Pokémon Trading Card Game, the animated TV series, home entertainment, and the official [English] Pokémon website."

The primary game developers are Game Freak in Japan, although if you look in the credits some other companies are involved for additional work and ports to different platforms.

I think all Pokemon games are developed by Game Freak except for Pokemon Go which is made by Niantic.