#4 Ronda Rousey does not debut
What We Know: Rumors have speculated that Ronda has signed with the WWE and will be debuting at the Royal Rumble event. Ronda has denied these rumors.
What Will Happen: Ronda Rousey will not debut in the Women's Royal Rumble.
Why: WWE does not typically bring in big name talent unless that talent is winning the event or at least lasting till the final two. See Chris Jericho's return in 2010 and WWE holding off on bringing back Randy Orton in 2014.
Ronda will still wrestle at Wrestlemania against Charlotte, but WWE will be wiser and have Asuka win the Royal Rumble to face Alexa Bliss, giving that match a little more hype. Rousey herself brings the intrigue and hype to her match with Charlotte. Thus, she does not need to win the rumble to make her match interesting with Charlotte.