I really want PUSA to get Maurice LaMarche (who plays the Brain in America) to voice the dub Pluto.
They won't. LaMarche lives and works in LA; Pokémon dubs in New York. LaMarche is also a longtime, veteran voice actor, likely with salary demands too high for what the Pokémon dub has any reason to pay.
Never underestimate the power of stupidity, of the one and of the many. Words to|live by