Anyone with any instructional time at all knows that every new pilot looks at the panel too much and has to be taught how to scan outside. It's perfectly normal and looking out is just another one of the skills needed to be learned. Transitioning to a new airplane people will also spend more time looking at the panel until they get the lay of the land and learn how to use any new equipment installed. Also perfectly normal. When one starts flying automated airplanes it becomes even more prevalent because the automation must be handled correctly and constantly managed to ensure it is in the appropriate mode for what you need it to do and properly monitored, so your attention must be split especially in a busy terminal area with lots of traffic and very demanding IFR procedural requirements.
But at the risk of repeating what has already been said, nothing in the TSB report indicates either pilot was deficient in their visual lookout but does go on at length explaining the challenges they had in seeing each other before it was too late. The report doesn't say whether either pilot rode motorcycles or not so we don't know if that was a factor. An omission on the TSB's part I'm sure.