As previously noted, WWE has plans to stack SummerSlam because they want a WrestleMania-level show in Las Vegas.
John Cena vs. Roman Reigns is still planned for the show with John Cena returning on the July 16th episode of SmackDown to set up the match. Another match planned for the show will involve Edge.
Edge is also scheduled to return soon and he is advertised for the July 16th SmackDown. WrestleVotes is reporting that he will be facing Seth Rollins, which confirms that he will continue to be a babyface even though they teased that he was leaning towards the heel side during the build to WrestleMania.
At this point, no other matches are confirmed but WWE would obviously love to have Brock Lesnar back. There is no deal in place for Lesnar but if he returns then a match with Bobby Lashley would make sense.
Another big name expected back soon is Becky Lynch.
Along w/ Roman Reigns vs John Cena for SummerSlam, WWE is planning on stacking the SmackDown side with another major matchup. Source says idea as of now is for a Seth Rollins vs Edge first time ever match.
— WrestleVotes (@WrestleVotes) June 21, 2021