#6 Sami Zayn
Sami Zayn went down with an injury back in June 2018 that required surgery on both his shoulders, which he successfully had. Before going out with his injury, Zayn had been feuding with Bobby Lashley, and had just come off feuds with Braun Strowman, Shane McMahon and Daniel Bryan.
So Zayn wasn't doing too bad at all, just like in 2018, he seemed primed for a prominent WrestleMania card position this year. Despite being out of action, WWE had aired vignettes for his impending return some months ago and reports had recently surfaced that Zayn was ready to get back in the ring and was just waiting on his return date.
As Sami Zayn returned to action on the post-WrestleMania episode of RAW, I don't see why they shouldn't have just had him return to WrestleMania itself instead. Zayn could have made his presence known in a match on the card, perhaps aiding someone in a victory, or could have at least come out at some point to cut a heel promo, which would have put him over better rather than on RAW.