#1. They need a main event

Like WWE Stomping Grounds 2019, WWE has one major problem - the lack of a worthy main event. Seth Rollins vs Baron Corbin was a main-event that had nobody excited about the PPV, but the addition of Lacey Evans added the unpredictability factor and Becky Lynch's involvement cemented it as a match that helped send fans home happy.
From the look of things, this will most certainly be the main event. Though it isn't confirmed yet, Roman Reigns looks to be teaming with The Undertaker against Shane McMahon and Drew McIntyre.
Cody has no chance against John Cena? Details HERE
While it could be argued that Undertaker & Reigns should main-event purely due to being bigger names, the fact that both titles are on the line means that the stakes can't really get any higher.
In that sense, it will be the main event, particularly because it's a huge "special attraction" match.
Also read: 5 major things you missed from WWE Stomping Grounds 2019