Would be cool to add.
I can say why we didn't do it though. The On_EnemyChamp_Kill lines were brand new then and untested by our team. So we weren't entirely sure how/if they would work and more importantly how they would be received by players.
So we didn't want to compound our bug risk and player perception risk further (For example by having the potential- quadra kill line playing over the pentakill line, the standard kill line, and announcer- line- All playing together at the same time 1% of time-- AND we couldn't even be sure players wouldn't prefer the announcer alone vs Jhin's voice!)
Our VO system is a bit byzantine and hacky -esp at that time -- and Jhin was made very, very quickly (about 75% of the time a normal champ takes)-- so there was going to be less bug fix time for him. It was brought up as a cool idea-- but dropped because of the time/risk ≠ the perceived reward.
[sg-soraka]