User blog comment:A.Darkbloom/Institute of War/Summoners/etc no longer being canon/@comment-4745915-20140909163040

They didn't have to rub the lore-invested community the wrong way and unnecesarily limit themselves by officially removing the Institute, League, and Summoners. They could have just gone foreward with the future stories they want to tell without recognizing the Institute and its trappings, because the Institute doesn't actually micromanage the affairs of Runeterra like so many of them want to claim. It simply isn't powerful enough. Additionally, its continued presence would have served as a built-in "Deus ex Machina" device for them to use if needed without it seeming like a writing cop-out because it already existed and would be integrated creatively.

The Institute is content to be ignored when it isn't convenient, and most Summoners are do-gooders at heart who are willing to remain passive when all-out Rune War isn't at stake. In light of those facts, the result of team's decision to take this official stance was to unnecessarily upset a bunch of people and unnecessarily delete from their story options a device that could still prove very useful at some time in the later future.