I realize this may sound off-the-wall at first, but Roman Reigns may make the jump to SmackDown Live during the Superstar Shake-Up. Roman, might jump along with Baron Corbin, because that is who he’s scheduled to feud with next (I know, I’m bummed too). From WWE’s perspective, it would destroy his babyface persona which is newly established after winning his battle with leukemia.
It would be destroyed because he would undoubtedly be pitted in a feud for The Universal Championship with Seth Rollins, and since Seth is a bigger face than Roman, and has been for longer, the audience may side with him. Rollins can work with new stars on Raw, while Reigns does the same on SmackDown. It also may freshen up his character the same way it did for AJ Styles in 2016.
After Corbin, he could feud with “The face that runs the place” before being put into a title feud. Reigns could then win the major title on Smackdown and form a heel faction with his cousins The Usos, and, at go at it from the angle of how they are not appreciated enough for all the work they put in. This could be a great way for Roman to expand his character.
From the perspective of FOX, as a big network, they thought they might be getting Ronda Rousey on SmackDown weekly, but now that is not the case anymore due to her desire to take a break from WWE and try to start a family with her husband, and with Roman Reigns being the company’s next biggest star, FOX will likely jump all over that. This is purely speculation, but it might be a good idea for WWE to put this plan into action.