Ranked: I know all other games adopt a 3 month or so Ranked "reset" cadence, but League was special because it felt like a sporting season. Its familiar, flexible, and intuitive.
Having 3 different splits waters down the merit, value, and prestige of the Ranked ecosystem because it resets and happens so often. It's like if the World Cup changes from every 4 years, to every year. Frequency isn't always positive, I mean look at the LEC, I don't even know wtf is going on there. They're dishing out trophies like Oprah and it just waters down the experience and achievement.
Summoners Rift: BYE MYTHICS, you wont be missed. Wish these Dev Updates have more information about SR. Better than the previous one though. /u/Reav3 said preseason was going to be big, I hope it delivers.