I disagree so incredibly heavily. With the retcon of the League of Legends, we aren't inclined to feel immersed. Obviously we care about the lore being chewed up and spat out like this, as now we don't feel any impact in our actions. This game is nothing more than that, a game. We aren't a part of it, we don't have a hand in any fights, and nothing we do feels like it's worth anything. Yes, these lore interactions really are worthless, yes this lore really is worth nothing, and yes, these backstory changes are really fucking stupid.
Being told that the Institute of War is fake, where great heroes gathered to test their might and where murderers came to bask in the glory of the killings... it's jarring to say the least, and rips me out of this game. I hate that. Summoners aren't real either, so what we're doing in game is actually like us playing with toys and saying "oooh boy look at how cool my cool Vayne toy is!!" Give me a break.
If you're really going to tell me that the Summoners, and Institute of War (which was the proposed solution to the Rune Wars, which was supposed to -EXPLAIN- magical issues in this realm) are all just fake and I have to get over it because it's all just hindering the story, then I have a really big problem. The lore is dead, because it has nothing to do with League of Legends. Maybe it was a little underdeveloped, but it was connecting the game to the story. That's just the people that are complaining's problem. You might not consider it as an issue, but if I wanted to play a game without any lore, or a lore without a game, I would play Doom or read a novel, respectively.