User blog comment:LivesByProxy/Yore Endless Possibilities: A Look At Lore & The Meaning Behind League of Legends/@comment-28205790-20160503090807

I thing the major problem for Riot to create a complete chronology of lores is that there are simply too many questions left unanswered. There are of course some champs who doesn't really need a very detailed lore like (obviously Lovecraftian) Voidborns, because the Void is supposed to be an unspeakably horrifying place, and dragging and dropping Voidborns onto Runeterra without specifying any reason other than their unfathomable urge to be in another world seems legit, at least for me. But the problem is, one can't simply do everything in this fashion.

An interesting fact is that, of the most recent champs released, many of them are supernatural beings or even deities within the Riot universe (Aurelion Sol, Kindred, Tahm Kench, Bard, plus the earlier Aatrox), naturally these beings won't necessarily be too engaged in worldly affairs other than having only limited or sporadic connections (AS confined by Targonian magic and Targon is his only problem within Runeterra, while the other four simply wander around everywhere, doing every bit of this and that along the way). These champs, free from any faction, would require very few lore renovations in future, and none of these five are interconnected in any way. Creating a Demacian or a Noxian champ, on the other hand, means that Riot have to think carefully how he/she would interact with people from these two factions, which are already many, not considering any possible connections with other factions. That's why Demacia and Noxus, two most renowned factions of the entire franchise, have not witnessed a new addition in the League for years. (Lucian, a semi-independent Demacian, was released in August 2013, and guess who's the latest Noxian? DRAAAAAAAAAAAAAAAAAVEN. June 2012.)

Seems that Riot is all into making champs but not into making lores anyway.