They did expand on it with "Phandelver and Below: The Shattered Obelisk," which I understand to be quite good. Unfortunately it seems like most other paths are ok at best. I'm currently running the Dragonlance adventure, Shadow of the Dragon Queen, and that's very much how I'd describe it: ok. There are some really weird omissions where the game doesn't have info you need to run an encounter as described, and the world-building and information included in the book is woefully inadequate to "color outside the lines" without making up lots of details out of whole cloth. For a book that represents the first Dragonlance adventure in many years, it's a disappointing introduction to the setting.

I regret to inform you that was released in 2014, almost a decade ago.

That's longer ago than I thought, but still just within the decade, so it counts.

I admit it's a depressing performance by WotC.

Only a true D&D player would rules-lawyer the decade definition like that.

Sounds like a rollplayer, not a roleplayer.

I'm actually not a D&D player; I'm currently involved in Shadowrun, Blades in the Dark and Pathfinder 2. Despite that, I don't consider it very controversial to count a decade as 10 years.

Lost Mines was a terrific pack-in adventure - I got so much mileage out of it.

I would love to see WotC publish more adventure booklets of comparable quality.