A number of Guardians on Xbox One and PC have been able to pick up Wavesplitter recently, despite the Trace Rifle being a Playstation 4 exclusive. Now bungie have announced that they’re going to be rolling out a ‘fix’ that breaks the weapon for any Guardian not on Playstation 4 until September.
Source: N4G PC Xbox And PC Guardians Getting Wavesplitter, But It's Locked