Lars Sullivan will be using The Freak Accident and the running sitdown powerbomb as his primary finishing moves moving forward, and not the diving headbutt.
The diving headbutt is a high-risk move that caused issues for wrestlers over the years, including WWE Hall of Famer Harley Race, The Dynamite Kid and Chris Benoit. Race once said he wished he never invented the move because of the long-term neck damage is caused him. The Observer noted that the diving headbutt is actually safer for the opponent than the sitdown powerbomb is.
It's likely that Lars will only bring the diving headbutt out for big matches or angles where they are trying to get something over.
Below are a few clips of Lars using the move in WWE NXT. Lars last used the move on Elias during last month's RAW attack.