This is even sadder than 
lore. Like come on are we going to get a new short story of him finding his mother because it can't end there.
But it is not clear that she died lol. She is lost.
It's unclear what happened to Nunu's mother. She could be dead or she could be alive. It's like what they did to Annie's birth mother in her new lore.
Riot leaving the fate of Nunu's mom unknown allows them to make it a plot thread that could be explore later in whatever way Riot sees fit.
This is even sadder than
It doesn't end here. With Willump, Nunu's quest to find his mother just began.
I mean, no one has said that she died... maybe she is alive somewhere. I doubt, but it is possible.
Imo Lucien shoudl find his wife and Nunu is mother. That would be so cool. (and i dont like bad endings - especially if its fantasy and can be changed )
I think it's implied more that she's actually alive, and that looking for his mom is what drives Nunu to be 'Freljord's hero'.
It's like the Entwives. We lost her, and we can't find her.
"This is so sad. Can we cover the world in ice?" -
.
She is nowhere to be found ! Not dead...Lets hope she is not dead [zombie-nunu-bummed]
