Well he did appear in the Universe comics. However, Botcon have now shown him, albeit as a cameo, to be part of the G2 cast. In Timelines#, Generation 2 Redux, his Machine Wars self is on the second page where Streetwise brings everyone up to date. In the bottom right hand panel, he's seen flying above Double Punch and Colossus. Botcon comics are considered canon by most of us. Plus, Machine Wars was comprised from unreleased G2 toys.