The official WWE website is referring to the WWE World Championship held by AJ Styles as the "WWE Championship" once again. The Championship has undergone a name change several times over the last few years.
The title was originally called the "WWE World Championship", then "WWE World Heavyweight Championship" once the "Big Gold" belt was retired and combined and since the brand split it's been known as the "WWE World Championship."
Just to confirm in case you was in any doubt...It's STILL a title! ;)