@RiotKateyKhaos Can i get some clarification on champion designs?

so i just finished reading the targon lore(whats out so far anyway) and overall liked it though it did changes all of the characters involved in some way which i'm a little iffy about after the whole miss fortune thing, but i was thinking about champions design specifically their visuals. is my favorite champ in the game. character and gamplay wise, so really don't want her changed. i was somewhat less scared about something happening to her like what happened to katarina, fiora, and ahri because i remembered reading an article written by a rioter about champion design philosophy and why some champs change visually more than others with updates. i tried as hard as i could but couldn't for the life of me find that article again. to sum up the article, it talked about how some champions(i think 10 or 12) have official "base designs" that solidify their appearance and say "this is what these champions look like". the one they was talking about most was riven and diana. this is "rivens official face" http://orig06.deviantart.net/6824/f/2014/014/7/9/riven_face_tutorial_by_knockwurst-d728f7a.jpg this is a video of the creator talking about what i mentioned above at 2:55 https://www.youtube.com/watch?v=QUuYD9tEQUs other champions that i have found with similar art are zyra http://st.elohell.net/public/chill/81486f57606c5b82ce0598de74b03e86.jpg syndra http://st.elohell.net/public/chill/4081ed413395ce78798f12c119782412.jpg elise http://pre03.deviantart.net/65c8/th/pre/i/2013/222/5/d/elise_the_spider_queen_by_zeronis-d5ihue1.jpg and of course diana http://vignette2.wikia.nocookie.net/leagueoflegends/images/9/93/Diana_Concept_2.jpg/revision/latest?cb=20120808100120

i started to doubt however when i remembered the ahri splash changes(i can semi ignore kat by saying that her face is messed up due to the awkward "super speed blur" effect), since i thought that this was ahris official face http://apollo-na-uploads.s3.amazonaws.com/1421842159112/Ahri_New_Dawn_concept_5.png since it appears in not only the "new dawn" cinematic(which was great, you guys should do that WAY more often) but also in the ahri statue, and mostly closely resembles her in game model https://na.merch.riotgames.com/media/wysiwyg/promo/ahri2015/Social_1920x1080_AhriStatue.jpg https://i.ytimg.com/vi/vzHrjOMfHPY/maxresdefault.jpg which is defiantly not the same fox girl in this splash http://ddragon.leagueoflegends.com/cdn/img/champion/splash/Ahri_0.jpg

so my question is this. is there going to be be consistency? do at least some champs(like riven and diana) have an actually identity visually in riots eyes? or should we all live in fear that our favorite characters will be "re imagined", into a completely different person at some point?