They've made a pretty emphatic statement re: plain Cheerios and cross-contamination. Shosh, I'd feel pretty confident that the risk there really is close to zero. If it weren't, (that is, if they were sharing lines), I would expect different verbiage. More like "We take every precaution, blah-blah-blah..." rather than "there is no possibility" since the legal liability is definitely different.
KWIM?
For us personally, it's the multi-grain Cheerios that we're worried about.