WWE is a weird place. Their foresight in TV production and gauging audience reactions is well known. They have seemingly attached a high importance on what name a superstar uses on TV. This has seen multiple character reboots, such as Isaac Yankem becoming Kane or Husky Harris becoming Bray Wyatt.
Even though the name is just a small portion of someone's character, WWE seem to enjoy changing and shortening names of their talent. If names like The Undertaker, The Miz, and Dolph Ziggler have worked, you would think any name is fine on TV. Nonetheless, we will be looking at 9 wrestlers whose names WWE shortened on TV.
#1 From Colin Cassidy to Big Cass

Did you know a top WWE Superstar just wrestled outside the company? More details HERE
Who remembers Colin Cassidy? Well, SmackDown's newest monster heel did have a very different name before he debuted on the main roster. Tagging with Enzo Amore on NXT, Cass went with the much longer name of Colin Cassidy. However, WWE Creative decided that was too plain for the giant 7-foot man, and decided to just have a word which emphases this.
Cass did use the longer version of his name for a few months on the main roster, having his name changed permanently to Big Cass after Payback in 2016. This seems like a good decision, as Big Cass sounds like a better name than the contrived Colin Cassidy.
#2 From Elias Samson to Elias

Elias has become one of the most intriguing heel acts on Monday Night Raw currently, as his 'Walk With Elias' gimmick is extremely over with the WWE Universe. However, WWE made the former NXT man lose both his name and gimmick.
Elias ran as Elias Samson back in NXT, and didn't enjoy a lot of success, as he left the developmental brand with a losing streak. He also had a gimmick as 'The Drifter' in NXT, and both had been dropped post his main roster debut. Speaking on the name change, Elias said: "It was not my call. I got up there. Got to Monday Night Raw. And, The Drifter: no longer. No longer call myself that, at least I can't refer to myself as that, and Samson dropped as well."
This name change has been fine, as everyone would agree that just Elias is a better name than adding that surname, which reportedly, no one backstage ever liked.
#3 From Luke Harper and Erick Rowan to Harper and Rowan

Another one in which one portion of the name was just dropped, Luke Harper's repackaging with partner Erick Rowan meant that they would lose their first names for The Bludgeon Brother's gimmick.
This is a directive straight from Vince McMahon, as he believes that they would sound more powerful with just their last names. Whether or not that has made a difference or not, ditching their relatively dorky first names may have actually made a subconscious impact on the audiences for the duo. Good for them.
#4 From TJ Perkins to TJP

The Cruiserweight Classic winner and inaugural Cruiserweight Champion won the crown under a longer name compared to the one he uses today. It's the same name he used on the independents, and an absolutely bizarre reason caused it to change to just TJP.
The reason, as reported by Bryan Alvarez of the Wrestling Observer was that Vince McMahon hates the chain 'Perkins' and doesn't want to have his wrestlers associated with something he loathes. TJP later tweeted debunking this, however, saying that he asked for the name change himself. But with Vince McMahon's penchant for changing things for such reasons, we wouldn't put it too far from WWE making this change for the aforementioned reason.
#5 From Adrian Neville to Neville

After dropping his independent's name 'Pac' when he joined NXT, Neville was forced to make another name related sacrifice when he went to the main roster. In NXT, Neville was known as Adrian Neville, however, WWE just dropped the first name when he debuted on the main roster.
The former Cruiserweight Champion has had no explicit reason for changing his name, with reports saying that he just didn't like the 'Adrian' part of his name, and others saying that Vince didn't feel like his entire name was marketable enough. (a trend which we will see later on this list too)
#6 From Big E Langston to Big E

The man who terrorized NXT and is heavily fancied by Vince McMahon to be one of the next big stars in WWE, Big E went from being Dolph Ziggler's bodyguard to part of one of the greatest trios in WWE history. In this evolution, his name also saw a subtle change when his last name 'Langston' was dropped.
According to Big E himself in a 2015 interview with Christain Rosenberg of AfterBuzzTV, the last name was dropped because Vince McMahon felt that Big E was just a more powerful name. "The word I got was that Vince thought 'Big E' sounded more powerful without the last name so you show up and sometimes you know with what we do there's a debate or a discussion or you talk more say so and it's a little more hands on. And in this case it was a matter of me showing up and this is who you are now so you deal with it."
#7 From Antonio Cesaro to Cesaro

Another dropping of the first name, Antonio Cesaro wrestler a considerable portion of his WWE career with his first name attached to him. He won the United States Championship as Antonio Cesaro, but in 2014 he saw that name change to just Cesaro.
There still has been no explanation for this name change, as this was a quieter change than the others. However, belief runs rampant that this name was changed for the same reasons as to why most name changes of this sort happen. Vince McMahon just thought that calling him simply 'Cesaro' will make it seem more powerful, and him more marketable.
#8 From Aleksander Rusev to Rusev

This is a name change that most tend to forget, but Rusev debuted on the main roster as Aleksander Rusev, but changed that name soon enough to be simply Rusev. This change coincided with his nationality to be changed from Bulgarian to Russian on WWE TV.
This change is another unexplained dropping of a wrestlers name after the wrestler debuts on the main roster. Rusev was one of the first few wrestlers to be put through this, and it set a precedent for how most wrestlers will change after debuting on the main roster. Marketability and strength of a single name may seem more important than we realise.
#9 From Bill Goldberg to Goldberg

Yes, a name shortening which actually happened before 2014. WCW removing the Bill before the name of WWE Hall of Famer Goldberg's first name from his billing is the true precedent for a pattern which has gained increasing importance in the last 5 years.
WCW, like how Vince McMahon thinks now, realised that the marketability of Goldberg would be better if his non factor of a first name is dropped, as the wrestler anyway derived all is personality from the last name and not his mundane first name. It started with Goldberg and has come till Apollo now, and will continue for years to come.