In the Transformation scene they sing "Everything will become clear to you when you see things through another's eyes." in Inuit. Well, when Kenai has his flashbacks to when he and Koda's mother faced off... he's remembering them at least partly in bear. He's hearing them from a bear's point of view, and everything finally makes sense now that he knows why Koda's mother did all of that.
When Koda's mother speaks in Kenai's flashback, he finally understands her - she's even talking in human when she stands and calls out for Koda.
At the Salmon Run, when they're playing "Pass The Salmon", all of the bears are telling stories of friendship and love - from the two bears now mating, to the big bear who's allowed a family of chipmunks to move in with him because he pushed down their tree. Totem of love, everybody!
When Tanana jokes about totems, everybody laughs, and she does too, but if you rewind her age appearance you can actually see that in her youth she may well have been quite attractive.
Tanana: When each of us comes of age, the Great Spirits reveal to us a totem that helps guide us through our lives. Some of us use courage to guide us, others patience. And some of us, beauty...
At the lack of a "Fridge Sadness" trope; a bear's lifespan is around 25 - 35 years, meaning that when we start out the movie by seeing Denahi as an old man, Kenai and Koda (and Nita) are all long dead.
They're essentially transformed spirits, not actual bears. Kenai and Nita probably would live normal human lifespans, but it's still Fridge Horror: Koda won't.
Also remember that this is the Ice Age: normal human lifespans wouldn't be, on average, much longer then a bear's.
Watch that word 'average'. Infant mortality in older times could be brutal but if you made it past 18 you could live to see 60+.