Almost everything in that image is identical from the fencing on the left to the arched stone temple looking things. Calling fake also.You are actually right.
Not from the same demo, but from Unity Blacksmith free assets:
https://assetstore.unity.com/packages/essentials/asset-packs/the-blacksmith-environments-39948
Pay attention to the bridge that leads to the buildings that look like a stone valley:
No look at the "leaked" image:
It's the same. It's FAKE.