#3 The ECW Championship has only been defended once
The ECW Championship isn't considered to be the most memorable of titles in WWE history, but there was the odd occasion when the company decided to defend the Championship as part of the main roster.
Back in 2007, the ECW Championship was defended the one and only time at Survivor Series when CM Punk retained the Championship in a triple threat match against John Morrison and The Miz. A decade later, it's interesting that The Miz is the only star who was involved in the match to remain contracted to WWE and he walks into the event as the Intercontinental Champion.
The Universal Championship is the only current main roster men's singles Championship that is still yet to be defended at the event after Kevin Owens was involved in the traditional elimination match last year and the Championship isn't on the line this year.