I know that Reds have mentioned in the past that they're not happy about the way the lroe is currently deployed. The journals and lore entries feel really detached from the game, and only lore nerds (like myself) really get the benefit of enjoying them, because we seek them out. Other people who might not be initially interested in that sort of thing miss out on something they might otherwise enjoy. So, to remedy this,m I've come up with a couple possible solutions.
I read somewhere that there may be some gameplay tips and interesting facts on the loading screen. This seems like a great opportunity to get some lore out there. Right now, I have a feeling you guys have already thought about that, but I worry that it will just be stuff that's already been established by journals and champ lore. It's fine to include that stuff for people that may not have read it, but why not throw some new stuff in there, too? It doesn't have to be anything big. As we saw with the hidden interactions on Shadow Isles, a lot of interest can be generated in the lore through a few sentences. Just build on stuff, provide a little intrigue, get people interested in what's going on in Runeterra.
Champion progression. It's simple. The more you play a champion, the more lore you have access to for said champion. Not only are unlockables a great way to get your audience excited about your stories (achievements had a similar effect on forgotten content in WoW), but it might even generate interest in otherwise underplayed champions. It could even lead up to a big cinematic at the end of each story. I know, there are 100 champions, that's a lot of work, but if you consider how many champions have intertwined stories, you could potentially have the same cinematics for multiple champs, or at least overlapping footage. This could go along nicely with a theater mode, which could overlap with the replay system (hint hint), and could be monetized by charging for increased replay storage space/time. This is probably the least practical idea, but I'm spitballing.
Simple. More League Dispute matches. Ionia versus Noxus was a lot of fun. With the rising interest in pro League, and the fact that you'll be having them on salary soon, I don't see any reason why we couldn't have more "all-star" matches throughout season 3, and have them inform the direction of the lore. Certainly, the "hyper-competitive" branch of League fans are likely the least interested in the lore, since they play the game as a competitive outlet and not to experience The League of Legends, and this provides some overlap for them to maybe get into something they otherwise would have ignored for the most part.
This is my favorite. A story mode. It works, essentially, like any other queue, except you can only pick champions from a given faction. Of course, this is nearly the same thing as the all-star matches I listed above, but it's something for the more casual player who might not be interested in pro-LoL. There's a few ways to do it. Have players pick their faction permanently, or at least for a considerable period of time, and have them fight for its glory. You could have the factions be randomly assigned at champion select. You could pull a players most-played faction in other game modes, and have the game assign them to a faction that would suit their champion pool. The story can progress for a given faction as you play through its "campaign", and win-rates for factions can inform the direction of the story, similar to the outcome of all-star matches settling major disputes.
Obviously execution is difficult here. Deploying the lore in a game that lacks a definitive story-driven experience is a daunting task. But I think some of these solutions, if done properly and with care, could really breathe some life back into the lore for the game. It also fits well with the way Riot, as a company, likes to involve its players and fans in the game development process. It's a way for us to give feedback to the lore team by simply playing the game.