Amumu's Lore is a great example of compromise between a Company & its Community.
For context, Amumu's Lore used to be a vague clusterf*ck. Nobody could agree on what Amumu was. Was he a Child, or was he a Yordle? People who liked Yordles tended to like to bundle him in. On the other hand, there were quite a few people that liked the idea of him simply being a Mummy Boy.
At one point a few Rioters were going to change his lore to specifically state that he was in fact a Mummy Boy (I think this was Season 3/4?) much to the displeasure of the pro-Yordle Amumu portion of players.
Riot's solution was actually quite genius. His current lore, to settle the argument, is to take the argument out of our hands. Amumu's story is now a myth within Runeterra itself - so ancient that not even the Runeterrans themselves can agree on his true origin.
What does this mean for us, the players? We get to believe what we want and nobody can tell us otherwise. We can throw him in with the likes of Azir and Renekton. We can included him in an A-Z Yordle-only Marathon. We could even speculate his spot on the timeline in relation to Gnar.
Thank you Riot for this, largely unnoticed, underrated and often underappreciated change.