My impression was that something like that was intended. However, this seems to be a conflation of different categories. The normal category that occurs in this sort of context is "not religious but spiritual" which seems to generally mean people sort of like what you describe but also who ascribe to various supernatural entities (e.g. god, ghosts, spirits, maybe faeries). When given the choice between "atheist" and something like "no religion" or "none" such people will generally not put down atheist. And such people look demographically very different from atheists and agnostics. See e.g. this Pew study. My impression is that the religion questions were not phrased in a way that showed much familiarity with the underlying demographics or how such questions are generally phrased. In this particular context that's ok because I suspect that there are a fair number of people here who are atheist-but-spiritual under your definition but very few people here who would fall into the "not religious but spiritual" notion that is a subset of the nones in the general population.