#4 The Superstar Shake-Up
Ever since the brand split returned in 2016, we have witnessed a WWE Superstar Shake-Up take place each year. Stars move from one brand to another. It's usually done to refresh rosters so as that we don't get the same match-ups. Big stars can only feud with each other a few times before it gets redundant like Reigns and Corbin's feud.
There were actually two roster-split events in 2019, first with the Superstar Shake Up following WrestleMania. During the Shake Up, Roman Reigns, Finn Balor, Bayley and Ember Moon were among the big names to join the blue brand. RAW gained AJ Styles, the Miz, Lacey Evans, Ricochet, Andrade and Aleister Black. It immediately reset both shows as well as the feuds that each star would enter.
The second was the WWE Draft which took place when SmackDown moved to FOX in October. Not every performer changed brands, rosters were altered once again.
The Shake Up should typically allow some stars to switch brands in order to get some better chances in a new division. RAW's current women's division has been ruled by Lynch, Asuka and possibly now Shanya Baszler. The women of SmackDown have been ruled by Bayley and Charlotte Flair at various point in 2019. Things will certainly change again once the rosters are shuffled following the Showcase of the Immortals.