Actually, there's a book with that exact title, 'Once Unwanted, Now Adored', and I just finished it last week. It's a contemporary romance, part of a series about a woman who gets a second chance with the guy who rejected her years ago. The ending is pretty much what you'd expect from the genre—they end up together, obviously. But the path there is what makes it stick. She's built this successful life without him, and he has to genuinely grovel and prove he's changed, not just say sorry. The final scene is at this charity gala where she's being honored, and he publicly declares his love, acknowledging he was an idiot and that her worth was never tied to his validation. It's cheesy in the best way.
Some people online said they wanted her to end up with the new guy, the charming doctor who shows up mid-book, but I think the narrative always pointed back to the original connection. The closure comes from her fully reclaiming her power in that dynamic. He doesn't 'win' her back; she chooses him, on her terms, after he's done the work. It wraps up all the side plots neatly too—her business is thriving, her found family is solid, and there's a cute epilogue a few years later with kids and a dog. Satisfying if you're into healed wounds and grand gestures.