I've been bamboozled by Udemy a couple of times, thinking a course was recently made, only to discover the videos were 10 years old and most of the content was woefully out of date, with a few "recent updates" videos tacked on at the end.

Whether this is a problem obviously depends heavily on the subject. Classical CompSci problems won't suffer from this, depth first search is still depth first search ten years later. But the framework-du-jour is often a different beast entirely 10 years down the road.

Perhaps they simply have too much content to be able to curate things properly.