When importing the model into the three.js editor, you can see the following warning in the browser console:
THREE.GLTFLoader.js:395 THREE.GLTFLoader: Unknown extension “KHR_materials_pbrSpecularGlossiness”.
The support for this glTF extension has been removed with r147. Use the following guide to convert the asset to the metallic/roughness model.
Sidenote: Sketchfab should update its glTF exporter since the KHR_materials_pbrSpecularGlossiness extension has been archived by the Khronos Group (which means it is no no longer recommended for creating new files).