For the Phantom 3 I'd like to see a course on how to really get the most fun out of it, also how to help get out of the most common tricky situations (trees, crashing, losing your sense of direction, losing your signal, strong wind, and plain old copter going rouge).
For the Phantom 3 Advanced it would be nice to see something on getting to know your distance limitations, common rules and regulations for flying, of course tips on keeping your quadcopter healthy and running smooth, helpful camera settings and how to really get the most out of your advanced phantom.
The Phantom 3 Professional should include the best editing tips for photos and video, which programs can help out the most with that, also how to achieve the perfect shot.
For all of these it would be nice to see some of the common problems and how to fix them before they happen. Also, which accessories are actually worth buying like the better battery chargers, gimbal protectors, range extenders for P3, blade protectors, and blades.
For the Phantom 4 of course getting to know the new quad and how to customize it best for yourself would be great, and how best to enjoy the new phamtom. Of course something that tells you what all the new features are compared to the previous phamtoms would be nice.