Let's start with the elephant in the room. After a long contract saga that in a way felt like WWE was holding him hostage, Rey Mysterio left the company in February 2015. Since then he has primarily wrestled for AAA in Mexico. That company is going through a tough time business-wise now, however. Despite recently turning up in Lucha Underground, Alberto del Rio's return to WWE shows that isn't much of a barrier. Rey Mysterio is the most successful pure cruiserweight in WWE history, plain and simple. He reinvented the game, standing out from the pack in the old WCW days and continuing to wow audiences during his 13-year run in WWE. The door has been left open for a return if it suited both parties. The divorce might have been messy, but there's no bad blood on the part of company or talent. Quite clearly, the Global Cruiserweight Series suits both Rey and WWE down to the ground. The master of the 619 is a well-respected veteran and is beloved by the wrestling audience, meaning his return would draw eyeballs towards the product. As well, whoever beats Rey in the tournament will be given instant credibility. This seems like a no-brainer.