Riot, I believe you when you say you're trying new ways to communicate lore.
You say the small lore descriptions, like the ones in the PBE right now, are just for tooltips that can be short, summarized, and easily conveyed. That's perfectly fine.
I just hope you have a short story in the works for us. The short story with Azir and Xerath was wonderful, but it's no easily accessible. The video series narrated by Nasus, again, wonderful. But these things need to be accessible within the game, and by that I mean the game client. You've released long entries for modern champions before, just look at Braum and Gnar and Rengar and Kha'Zix, champions unrelated to the League completely.
These short entries are fine for tooltips, but please, I hope you have more coming. I'll give you the benefit of the doubt, again, just please.