I had thought about this idea earlier, and with the supporting role having their Pokémon out, it made me think more into it. However, like one member stated earlier, it wouldn't be the best of ideas knowing we could possible see their strongest Pokémon out before battle. So, to not ruin the fun of surprise and to keep the game in step, I wouldn't have my hopes up for anyone but the main player and supporting character to have their Pokémon outside. Not to mention, for the other supporting role, we might not battle against, but with them at times. So, showing their Pokémon wouldn't be a big deal like it would for Silver or a Gym/Elite's Pokémon. However, the idea always seemed pretty nice to think of and at least for Silver it would be a nice addition.