I don't think it's astroturfing. I've always heard Michael Arrington explain that his ideology (and I imagine what he tells his writers) is to write about what interests him, not worrying about the audience, saying readers will either come or not. With that view I could see Techcrunch writers in a group discussing things and that same sentence with Quora being used, since they live and breathe new tech. However, I think it's always good to question publications, as times and things do change.