Honestly, nothing. League's lore and emphasis on just having this generic fantasy world is, from a writer's perspective, one of the dumbest things that has ever happened to this game. League had this great thematic hook with the Institute of War and all these city state interactions and summoners and it was unique, it was interesting, it's what the damn game is named after! At this point League should just be called, "Fantasy Fighters" because that's really what it is.
The fact that they scrapped years worth of lore because, "It was limiting" is total bullshit imo. Having a theme that's present in your entire world and dictates how things happen is not stifling, it's an enabler. The fact that the Institute was this political gladiatorial arena was so damn awesome and it still allowed a great number of interactions. There is literally no champion released to date that wouldn't have fit within the old lore and the "Shurima update" for Azir would have worked just fine in the old lore.
Not to mention having this central thing working to preserve balance and keep another war from ravaging this world was great and could have opened up a lot of interesting dynamics between players. People like to poke at the idea that Kat and Garen are interested in one another or have this secret relationship going since one is Noxian and the other is Demacian and they're mortal enemies. But guess what, that simply cannot exist anymore in the new lore. Kat and Garen would never meet each other outside of a battle that would end in one of their deaths.
Same goes for Twisted Fate and Eve. Instead of constructing an interesting and engaging world with real characters in it.. They're going for fantasy tropes in a generic world that supports nothing but one of lores that are there only to make a champion seem cool so that people buy them.
And on another note, why are they even called champions anymore? They don't champion anything because there's nothing TO champion! They're just named characters in a story that.. Honestly no one would read if it was in any other form.
As a long time creative writer, the new lore is just a shadow of its former self and it's probably one of the lamest things they've ever done short of trashing the journal of justice. The League judgements gave us insight into these characters, the Journals let us see what goes on outside of the rift. Now all we have is a 2 minute animation about Bard doing honestly nothing besides make pretty lights show up. It's bad story telling and bad writing.
Can you imagine what Orianna's lore would be like if she was released today? It'd be a damn trainwreck. "Some girl gets killed by -insert generic thing that's not tied to anything here- and her dad goes mad and makes a robot that's, for some reason, a killing machine." It wouldn't make a lick of sense.
I honestly wish I could spend a few months with Riot's Lore Team and just see what these professional level writers are even thinking, because as it stands I feel like these people have just accepted that they aren't a team but a group of writers that want to make their own separate things and to make all these whacky and sellable characters something had to give. It's just frustrating to watch lore and stories I loved drift away into just memories. The day Sona doesn't say, "Only you can hear me Summoner" is probably the day I quit league.
to be in the position he is in today, Leader of Noxus. Without the JoJ, swain would never be the face of Noxus like he is today UNLESS RIOT RETCONNED IT.
's lore so he is just some crystal scorpion in the Shurima Desert that is quiet territorial. When what would been easier to do is simply EXPAND HIS LORE so that Skarner went to the Shurima Desert only to discover that more of his kind lived there, unprotected, and which is why he is so territorial now and is in the Shurima Desert.
for 
speaks in musical notes and Bard's message would fall flat on its face. Yet for Bard to interact with Zilean at all means that he is involved in the affairs of Mortals.
