I think that's up to the other league's commish Skull. I don't think there is currently any affiliation though.
I don't really see a problem with rookie teams overall, but there is a sense of 'well i'm going to get to around 1400' that comes with it.
My friendly league did that for a few seasons, only rookies with new rookies coming in next season on the restart. It was refreshing to play different teams but development is severely limited and some teams just aren't that much fun to develop. "gee... should i take block? or... block?" Good for learning yes, but many coaches here are NOT 'just learning'.
That format favors teams that have early starting skills, cheap rerolls, cheap players that can get a bench, or all three. Teams like Chaos, Nurgle, Woodies (to some extent), Vampires, etc are disadvantaged trying to catch up to teams with good starting skills like Humans, Skaven, Dwarves, Norse, Amazons, and Orcs. I'm not at all surprised by the Dark Elves winning. They start with four blockers nearly always and have early access to dodge with agility 4. Similar with humans, and undead (2 blockers, 2 dodge, 2 str 5 and cheap rerolls/lineman). Lizardmen are the anomoly, but can start with a nearly full roster of strength 4 AV 9 monsters backed by dodge.
the 6 games in CTA set everything akimbo however. 6 games is more than sufficient to close the gap for some exprienced coaches and a little luck in winnings. It brings some diversity that i think is refreshing.
While I think I would still play if an All-rookie format was adopted again, I don't think i would play a slow developing team, and may not stick around after a few seasons of throwing teams away.
then again, I don't play in the OCC or any other 'perpetual league'.