Imaro
Legend
A shorter-than-full length but narratively complete adventure that is designed to not overwhelm potentially new players or DMs with complexity or an overly wide sandbox, which doesn't require extensive knowledge of a foreign setting, and a trimmed down ruleset that only features what is relevant, plus dice if you don't have them. I wouldn't say teaching is the goal of those products. Also, what @pointofyou said.
I fail to see how teaching isn't the goal of those products... they enable someone who has never ran a game to run a game... that's the essence of being a DM.