Yes, I agree that all NLP must include some computational model. However, it is an interesting distinction to the reader of this article that the natural language engine is not based off of a linguistically derived grammar - like Powerset, and many of the larger, more notable NLP efforts.

This is the point the author was making. Had you not paraphrased the article to skew the intended meaning of this observation, it would have taken on a different meaning.

The actual text: "It doesn't simply parse natural language and then use that to retrieve documents, like Powerset... Instead, Wolfram Alpha actually computes the answers to a wide range of questions"

Computing the answer for 'what does a string of natural language mean' and 'what is the intended answer of the question being asked' are 2 different things.