TLDR: just jump to the last paragraph
After a few of the most recent Lore updates (Kayle/Morgana, Shyvana, etc.), I think I can finally articulate the ... issue between the original IoW-based lore and the current lore.
The new lore is higher quality. Each individual bio, short, description, and setting piece are obviously and unilaterally crafted with more time and detail spent than the original stories and bios.
However, the new lore lacks the unifying heart (specifically when compared to the IoW-lore). Riven's story? Good story, well written. Doesn't feel like it actually fits Ionia. Or how Riven feels ingame. Or feel interwoven with the other Ionia characters. It's just Riven's story. There's nothing 'wrong' with that.
Riven's old bio? Super short, super simplistic. Barely anything there! But it was just a nub for your brain to chew on. Spin on the 'old soldier seeks redemption' arc, or a ronin story. It's a snapshot, a blast of info to your face, but small enough not to get lost in confusion. And it would make sense that a character seeking redemption would work with an organization trying to help maintain world peace, while using the skillset she's good at (so she fit into the IoW logically and easily).
Kayle's updated lore isn't 'bad.' But it takes a character that was a sincere 'holy paladin/angelic' archetype, and turns her into a hyper-fascist zealot. There's literally no room for error with new-Kayle, her voice lines make that veeeeery clear (but props to the lore team for having her new background on the site, and her ingame voicelines be cohesive! That's progress!). An angelic/paladin character would have obvious reasons for wanting to help the IoW.
Now why do I gave a @#$% about the IoW? It was the unifying theme and the unique flavor. Was the specific setup a bit messy or silly often? Oh yes. But actually incorporating ME into the story in a way that still allowed for the characters to be off in their own world outside of the 'game' was downright inspiring. No other game actually offered that. When a champion would actually addressed me? I really dug that.
With the IoW removed, the actual plot, narrative, and setting are... more free, and the individual elements have been produced with higher quality, but nothing is hooking me. Nothing sticks in my head beyond any OTHER reasonably entertaining fantasy setting. Instead of a disparate and various cast of equally myriad origin, we have simplified and homogenized origins, with a few snapshots of higher detail focus.
In short? The IoW-lore was an ugly shell around a glowing heart of inspiring fun and flavor. The current lore is a beautiful, finely crafted shell... around... nothing, really. It's just another fantasy setting. I'm not in it. It's another story I can enjoy with a few minutes of my time... but the character I play doesn't know I exist anymore.
And that's sad.