#1. To establish Rhea Ripley as the next big star in WWE
Rhea Ripley is one of the next big superstars in WWE and that's been clear for a while now. She had a great year in 2019 and before, during and after WarGames in November, she's become one of the most rapidly improving superstars in WWE - male or female.
It's clear that they view superstars like her, Bianca Belair and Keith Lee with high regard based on the way they're portrayed in their brief crossover appearances. For Ripley, she was given a big push before Survivor Series 2019 as well, beating Charlotte Flair and Sasha Banks.
Even at Survivor Series, she won the Elimination match for her team. Her momentum would take her to the top of the mountain in NXT - where she dethroned Shayna Baszler and ended her long reign of terror.
While it would be a big stage to hold a title change, the general logic would be that Charlotte Flair can establish Rhea Ripley as a major star if she loses to her at WrestleMania.