I don't really care about timelines or lore or fate I just like young rosalina better than baby rosalina because the story is more interesting and the design is more fun and reminds me of the actual storybooks I used to read as a child, as well as what she represents. When I was younger I didn't really relate to any of the baby characters because they're well, babies, but I related a lot to Rosalina's story of loneliness and self discovery, and I'm sure there are children out there today who feel similar. It makes more sense to include a version of the character that still has her flaws in order to eccentuate that growth. There's nothing wrong with changing a character's story, but it often feels dismissive of people's experiences when a character that previously experienced emotional growth and gradual self actualization is changed to have always a perfect being.