That can, should, and does, vary by as many people as there are involved in NCAA officiating. The biggest goal of a pre-game is to get people focused on the task at hand, and to set aside distractions until your job is complete. How that is accomplished is up to you, and is largely based upon the personality make-up of the crew. Some folks like to have simple, informal, but thorough discussions about topics of interest. Some folks like to have more formal presentations on specific rule and/or mechanics issues. Or a combination of both. Some like to use, or include, a crew quiz format for their pre-game.
One of the biggest decisions that needs to be made is when to conduct the pre-game, which may be driven by when you are required to be at the game site. If this is an FBS level crew that arrives at the city of the game the day before the game, you will probably have video review, at least, the night before the game. In my early FBS days, we were expected to arrive at the stadium 3 hours before KO, which left a lot of time to have to fill, so we used that time for much of the 'paper' pregame - bulletin, rule, mechanics, etc., reviews. In the later years, we were only required to be at the stadium 2 hours before KO. So, for day games, we did almost everything the night before (video, 'paper' pre-game, etc.). For night games, we would review video the night before, then meet again after breakfast on game day for the 'paper' pre-game. In either case, we would have a brief "get focused" exercise at the stadium (like a crew quiz).
For the hotel pre-game, we would often perform self-critiques of our previous game. Describe what we did well, and what may need some work. As previously mentioned, quizzes, with thorough discussion of pertinent rules/mechanics, seem to work well. But, assigned topics to a couple of crew members each week also works well.
Be creative. Although probably not truly original, one crew member would conduct a Jeopardy format quiz/discussion. We always liked that.
As previously stated, the goal is to get focused. The day of the game is too late to truly 'learn' rules - that needs to be done during the off-season. Pre-game is for mental focus and elimination of distractions.
Good luck.
Robert