Yeah we could do many things but we need to make them in sync. You've already seen Red on 2-3 times even before finishing Kanto and now that makes the question where he is after beating elite 4. Will he be on on Mt. Silver and waiting for you. Will he be with Green or Blue, will we make Blue(actually Green, but sometimes the translations are off so green is blue and reverse) too. So many debating still needs to be done.
But we will definitely have Red somewhere.