Kai'sa E CD Reduction with Runaan's

I played a game today with Kai'sa while experimenting her build with Runaan's hurricane to see how it interacts with her passive. Runaan's does interact with stacking her passive on multiple people but then I also noticed during the game that Kai'sa's e cd was getting reduced much faster than usual when I was hitting multiple minions via hurricane and also during teamfights when hitting multiple enemy champions. So every time I hit at least 3 people/minions the e cd is reduced by 1.5 seconds rather than the usual .5 seconds. Is this interaction with Kai'sa supposed to be intentional because if so, this will make enemy have a much more difficult time counterattacking Kai'sa since her E will be up more often with runaan's especially with her evolved e giving invisibility? I can try to put a replay link later on though it will take me time to figure out how to add it on this page, and I'm a little busy atm let me know though if you do.