I would see your point if you cut the head .060" and put an M cam in it with the pathetic lift it has, but if you cut the head and still have a cam with any kind of lift, yeah, it'll still be usable AND be interference. If you have .030" from valve to piston on a bone stock setup (SWAG, varies with cam obviously), you trim .035" off the head, yeah, it's interference. If you trim off .020" (min-spec on the 530) and go from a stock head gasket at .049" compressed to a tight squish gasket at .030", then it's interference, but the head sure as hell ain't a door stop.
IPD cam in mine right now, head was trimmed .010" (still .010" above min-spec), block was decked .005" to get desired piston height, .035" cometic, mine is no doubt interference.