You're missing out on possibly thousands of dollars right now Riot.

How? Five letters: books. I'm not kidding guys, seriously.

Let's take a step back from out inward centered view of the League of Legends game and look at some other game with a focus on lore. Let's start at the master of story since about 1996: Blizzard Games. Yes I know a ton of players are fed up at Blizzard, me included, but you've got to hand it to them, they are true story tellers through their lore, and only about 40% of it is conveyed through gameplay. Their lore with World of Warcraft stretches back decades but what's really important here is that the whole depth of the game's lore comes from their first few books. In fact, in my opinion the entire base of the lore come from the collection of four books, The Warcraft Archive. And then you have Starcraft, which is less of a lore heavy game but its story kicks butt, and then there's Warhammer, which is even less of a story focused game.

Back to League. We all know that you're hellbent on keeping the lore separated from the gameplay and that's a good decision in my book. Yet rare is the lore that actually is interesting enough for me to vest my interest into. The only real example is the Twisted Fate/Graves lore. Now for these lore retcons. You try to make them epic and all that but you seriously dropped the ball for me on the Shurima one. freljord was good, but Shurima was terrible because

1. The character summaries suck. No really.
2. The characters created weren't really in depth at all. Riot, if you're version of keeping the lore separate from the game is these retcons I'm telling you now, it's not good enough and it's not enough. You need to give us more.

The perfect answer to me is to have books written. Get Christy Golden on Noxus, Richard Knaak on Shurima, tell us about the political intrigue between nations, the role of our champions in them, and the intense battles occurring. Don't just talk to us about past glory and say "they're here now, and their doing stuff..." show us their glory and their power, and why they fight. This is what worked with the orcs in WoW, in Lord of the Clans Christy Golden showed us WHO the orcs were, and that created another level of depth to the whole game.

TD;LR: Write books and show us your lore, don't just retcon it.