Sounds like to me you're more interested in seeing characters that has been mentioned or referenced in other parts of the lore over the past few years (cough
cough) rather than getting completely new & original characters not brought up before.
You're more interested in learning more previous hints or potential plot threads that involve those characters. Completely new & original champs aren't hitting the mark for you because they add nothing to those threads you want to see more of. For example, it's like preferring to see the Ruined King become a champ or getting a champ related to the Ruined King over Riot introducing a new character with no ties to pre-existing plot threads.
Honestly, all I can say is: Ok. I mean, if that's what you prefer, there's nothing to really say. Riot has recently shown that they're will to bring back those old, teased characters & make them champs cough
cough. But not every character needs to add to some pre-existing plot threads or fill out some pre-exist hole. That's not how a world with a shit ton of characters work. Some champs needs to have some more personal & smaller scale stories that doesn't add to a shit ton of other characters' stories. What they're doing is mixing it up. Add some new & originial characters with no ties to bigger plots while also adding characters related to ongoing plot threads.
And I will say this. Champs like
&
do add to the lore. Sure, they don't add to any subjects you might be interested, but they still add to the world of Runeterra & there respective regions.