They won't fix it. I contacted Support way back, when Janna's ultimate duration got reduced and she basically just shouted in the air after the effect had ended (provided recorded proof)...they refused to acknowledge it even was a thing.
Silently, some patches later, it got "fixed" anyway - they just cut the SFX, letting it end abruptly (no animation change though, so she's just flailing around silently now).
Also, she's outright lying - as an ARAM OTP, she still tells me I can expect to see dragons every 6 minutes.
I have waited and waited, but I have never even seen a single one on the Howling Abyss. :|
On that note, I recently tried contacting them again about Dragontrainer Heimerdinger's dance SFX, and how it's barely audible (after making a thread that got no reponse - what else is new - and sending a bug report), and again providing recorded proof and comparisons.
...They basically told me to get stuffed.