#4 To signal the fans that AJ Styles and Seth Rollins may soon be swapping brands

AJ Styles and Seth Rollins have been the faces of SmackDown Live and RAW respectively since the brand split took place in 2016. While AJ Styles has won the WWE Championship twice on the blue brand, Seth has won the Intercontinental title on two separate occasions on RAW.
Both AJ and Seth started working as heels on the show and turned face due to their immense popularity amongst the WWE Universe. Given that they have been running their shows for the past 2 years, it can be understood that they have run of opponents and a swap between the 2 superstars can help the Creative team book some new feuds on WWE TV. Having AJ Styles battle against RAW's champion Dean Ambrose in the match and Seth Rollins battle SD Live's WWE Champion Daniel Bryan may just be the first step of this switch.