Suggestion: New Champions be Disabled in Ranked for a set Period of Time?
Reason 1: No one knows how to play the champ. Experimenting with new champions and trying it out in different roles should be left in custom games and/or normals. Ranked is competitive and it doesn't make sense to introduce a new champion no one knows how to play or play against.
Reason 2: Balance issues. Since it is a new champion we have no idea what it's impact will be on rift with the plethora of different variables that can take place in each unique game. Every time a new champion comes out, more often than not it is either highly overpowered or just plainly underperforming. So then why introduce it in a competitive setting?
Reason 3: The novelty appeal. People play it because it's new. It doesn't matter if they know that role. It doesn't matter if they know it's a weak champion. It doesn't even matter if it's their first time in a ranked setting. Of course it's a first time for everything but why in ranked? Try it out in normals and play it for fun there.
Reason 4: It is most likely going the be banned unless both first picks decide to play it. Why even make whichever team waste a ban on it.
Ending statement: These are just my opinions. I just happend to notice an "unhealthy" pattern with each champion release in ranked.