Haven't they done it already?
Yes I know people didn't like what came out. Is that why you're going there again? (Just to know) From what I know it was some other guy who was rushed to do it or something. Clear me out
Sharjo2 votesThe whole reason is likely because everything went wrong with the release, so they're fixing what's broken. Not sure if there'll be any extra story or if it'll be just filling in the currently existing blanks, but as seen with Kalista; they'll put out the new bio style and have the short stories they wanted to release as a part of that.
frigginmurlocs2 votesThey also covering other Shurima champs like amumu and Rek'sai
UNSC1 votesnext champ is from bilgewater
ModWulf Helhammer1 votesNot necessarily champions, but lore
Rito Staff1 votesI thought they had been updated :| (Because I'm from 2014 gen and when Shurima things came out I thought that was an update, hadn't read before that)
GreenLore1 votesno,they just replaced the lores of some shurima champs with their short lores,meaning that 
etc have only a few sentences as their lore(
&
are the only ones who got a bigger lore piece).
They did prepare some lores for these champs(amumus for example was leaked),but didn't manage to put them on the official site due to tech issues. Now the lore-format changed again,meaning that they'll probably have to update the lores that they originally prepared again. (the lores they prepared were most likely similar in style to xeraths&azirs lores,so they were most likely a short story,meanwhile the new lores consist of a bio and a short story,meaning they'll have to create the bios now too)