I did a quick search of Trek 2200s and found that all of the discussions were about bikes equipped with Shimano hardware. So your bike was likely outfitted with Campy by a Local Bike shop or a previous owner.
Not necessarily. For one year in the mid or late 90's Trek factory spec'ed one of their carbon-tubed/Al-lugged frames with a Campy group (Athena I believe) more as a protest to Shimano's dominance than anything else.
They ran into problems because Campy wasn't used to providing OEM components to such a large scale manufacturer and couldn't provide the necessary volume and on-time delivery. The experiment ended part way through the model year when Trek threw in the towel and built up the remaining bikes with Shimano components.
I remember seeing this particular bike in a couple of bike shops (when it was a current model) built with both Campy and Shimano groups. When I asked why, that's what I was told.