I was looking at getting it for my kids just last week. Went through a bunch forums, reading through what people are saying and the overwhelming tone was that it's just not good. An ad-hoc collection of tutorials with no overall structure and that are more confusing than helpful. Too complicated for noobs, too trivial with those with a bit of experience.
If anyone has a firsthand experience with Unity Learn, I'd love to hear about it, and I'm sure others will find it useful too.