Google ended up incorporating it into some of its products such as it's spreadsheet service: Google Sets, Still Available

The closest thing I can think of to replicating it in Mathematica is to use the Entity framework. So for example, If I went to find a list of things like "Harry Potter", I would evaluate:

EntityTypeName@Interpreter["Entity"]["Harry Potter"]

This returns that Harry Potter is of type fictional character. We can ask for a list of example FictionalCharacters or we can maybe check to see which FictionalCharacter EntityClassLists contain him and return other Entities from the list.