#1 Sami Zayn appeared for Kevin Owens' storyline progression
Kevin Owens has essentially become RAW's top babyface. His storyline with Seth Rollins and AoP is the foremost feud on RAW now that Brock Lesnar won't be around until January 2020 and from the look of things, he's getting the biggest babyface push this year.
He's had a lot of start-stop pushes on SmackDown and while getting rid of Shane McMahon was a big achievement, it's no secret that he hasn't had the best 2019. Moving to RAW in the draft was the best thing that could have happened to him as he's now featured in the most important storyline in the company and after the happenings of the night (spoiler alert), it's now going to be the hottest rivalry.
Corey Graves deleted his Tweet! More details HERE.
Sami Zayn's appearance may have been a one-off and it made sense from a storyline perspective, especially since they were last aligned together before being separated by injuries. It was likely to help Owens' character progression as a babyface and give him that edge. Sami Zayn and Kevin Owens' paths will somehow always cross.