Yes, we have had this label offered by friends/strangers several times for our ds, and spent time/money/energy/worries over the whole thing. Turns out he does have some social issues but not aspergers. Nor Adhd, another one suggested a few times.
My personal scale for 'obsessive interest' in a topic is probably not one to judge by, but our ds, while very interested in certain things over the years, never approached what I would call 'obsessive'. (This was a word used in one of the many assessment forms we've filled out)
I think you are right to completely rule this out with the GADS assessment, if possible. Sounds like some folks will still have their own opinion on the matter, but the school hopefully will respond more appropriately, and not spend further time on this question.

If this article you mention is available on the web, please post, I would be very interested to read it.