#2 Kevin Owens was at a different show
I would like to thank James Elston who wrote in with this piece of information. Kevin Owens was at a different show when WWE RAW Reunion was underway, which is why he wasn't in attendance.
Owens was part of an event in Fort Myers where he did deliver a Stunner but in front of a significantly smaller crowd. So much so, that I can't even find footage of the same online, even on Twitter which is usually filled to the brim with GIFs and clips. I really do wonder if this was a wise decision on WWE's part as I'm certain that Owens would have been a better fit at the RAW Reunion.
But what ended up happening is that Owens interrupted an Elias segment and had him eat a stunner to the delight of the crowd. That's what you get with split rosters.