If done right, Young Avengers and Champions can co-exist, show as the teens who still have some oversight VS the teens striking out on their own.
Heck it would be even more poetic of Young Avengers consists of a roster that is all their own, while the Champions, the non-authority, have the members that are sprung from their progenitors. Otherwise yeah, not a good idea to take the current Champions out if it, especially since most of the members made a big deal of quitting the main Avengers to begin with.