In norms, I completely agree with you. In ranked? I think ALL new or heavily reworked champs should be put on a track of PBE for 2 weeks then live servers put it on restricted status for one 2 week patch. Only norms for those first 2 weeks on live. Maybe I want to see how the boards say to counter Neeko before I use my ranked LP as a beta test on a champ I am unfamiliar with. And maybe I don't want a person taking the newbiest champ out on my team in my ranked games.
But in norms? definitely. it is the place to learn these things.