I can't imagine how Chespin would be solely responsible for TR's blastoff. Is it seriously that important to you?Or they could end up in a mysterious pond where an old greninja turns him off the idea of evolving for good. Froakie does get hydro pump early as a consolation prize.
And I say chespin needs the honors of blasting off team rocket. Blaziken can get rid of the robot, but chespin needs all the wins he can get while he's still relevant.