So as we know and have known for a year that the Universal Title Match will be Roman Reigns vs Brock Lesnar. Different sites have different stories about what happened on RAW. Some say WWE told Brock and Heyman not to come and that Reigns would shoot on Brock and his contract. Others say that WWE did not know whether or not Brock would show and had 2 scripts, one with the Reigns/Lesnar confrontation and another without.
WWE is also worried about the release of the information regarding Reigns and steroids. It does seem that Braun Strowman is now in limbo because he's the insurance policy so to speak as they could add Braun and make it a Triple Threat. Or if something happens with Brock, he vacates the title and it's Reigns vs Strowman for the vacated Universal Title. Or if needed, Brock vs Braun if they need to remove Reigns.
http://www.ringsidenews.com/2018/02/...ia-main-event/
I actually think much like how everything righted itself at Mania 30 in New Orleans, things could right itself with Braun becoming Universal Champion. With Brock in limbo, and most certainly if the steroid situation with Reigns is devastating, they don't want the bad publicity of parading him as the new Universal Champion with a steroid scandal surrounding him. Meaning much like the last time Mania was in New Orleans, it will end with a bearded hero that the fans are behind and want to see as Champion, walk away as Champion.