Depends on the champ. Most have a little cut out of the final record. Maybe 5% to 10% of the lines.
Jhin was sorta an epic-- because of production timeline issues we intentionally tried to cover all bases. So probably 30% of his recorded VO never saw the light of day-- including the extremely disturbing haikus (sob) which were recorded for his recalls."
I don't know about you, but i'd really like to know what was there, especially the recalls and read it in his voice.
Lilly May1 votesSame here, Jhin is my favorite champ and those haikus seriously peak my curiosity. I wanna hear them!
Dryditch3 votesPique*
Sorry, pet peeve.
Pique comes from a French root meaning "irritate" or "stir up," which is why we use it today in that context.
Sancre1 votesNever knew he had Haikus in those unused voicelines, now i have to hear them...
JustMonika131 votesNever! Because haikus are imperfect! They only have three lines! A disgrace to art! 
rtbf2256182411 votesThe Artist is the final piece. A voice.
ProtestantCaesar1 votesI wonder if his selection quote is a part of a haiku.
In carnage, I bloom Like a flower in the dawn What is the third line?
rtbf2256182411 votesAs their flesh ascends.