10 Things That Could Happen On The Raw Following WWE WrestleMania 39

Roman Reigns' current arc can't conclude any other way than with The Rock.

A Sami Zayn rematch, with Zayn going over, holds no significance without the Undisputed Universal title, which Reigns isn't going to hold for another year to drop at WrestleMania 40 - the reign ends at 'Mania 39. He can't disappear after a loss to Cody Rhodes; his on-screen presence in the last three years has been too serious to allow such a cop-out. Jey Uso works, but not as a Final Boss-esque opponent.

The Rock is the only feasible option.

This is what Dave Meltzer had to say on Wrestling Observer Radio, implying that Roman Reigns vs. The Rock isn't ruled out entirely. It's just ruled out for now (h/t to WrestlingNews.co):-

"The same goes for Dwayne. Dwayne could be there in some way or fashion. There are people going, 'Oh, don't you think it's a swerve they keep saying it's not a swerve?'. It's not a swerve. I've been told this for a while. There's always the 'Maybe it's a secret', like the Pat McAfee thing, right? Only a few people know. We're past that point. Cody Rhodes won the Royal Rumble. He's getting the Championship match. It ain't Dwayne anymore. Dwayne's not wrestling anybody else unless it's a three-second match. He did not feel that he had the time to get in the shape that he needed to be in to do a WrestleMania-calibre main event, and he left the door open for next year."

Roman Reigns vs. The Rock would be a massive get for WWE's season-ender, and would at least ensure the latter's official retirement match isn't against Erick bloody Rowan. The Rock's return would break the Internet, it would sell tickets, and it would create the highest legitimate attendance in WWE history for some time. The match is happening at some point.

WrestleMania 40 may be that point, and the Raw after WrestleMania 39 may be where it all begins.