#2 Lacey Evans

Of the superstars originally slated to 'be new to the main roster' at the beginning of the year, Evans received the most focus. While her act mainly involved her walking up and down the ring ramp, the fact still remains that she appeared on almost every episode of Raw and SmackDown between January and now.
She's already in the midst of her first push, becoming the first challenger on Raw for Lynch's Raw Women's Title. It's a better direction than had it been Natalya, but Evans is already a better character than half of the women on Raw. Her heel type is different than most of the 'mean girl' types like Alexa Bliss and the IIconics and she's not a bully type in the veins of Nia Jax or Rousey.
If she defeats Lynch at MITB, then that's the proof of how she is viewed by Creative. She could just as easily lose at the PPV but be the reason as to why Lynch loses the title to a cash-in.
Evans is a new and fresh addition to the roster and the division, so I'm not against more of her in 2019. How far she can go is up to her and her booking, but she's already been booked stronger than someone like Bayley.