Hey John,
This is a good question! The Sodexo staff you describe would be considered an "outsourced activity" and thus would technically not *have* to be counted in your inventory to meet the requirements of PCC reporting. However, as is described in the ACUPCC Implementation Guide, campuses are encouraged to investigate and report on additional Scope 3 sources to the extent possible.
One question I would have is how much influence does your campus have in providing solutions to reducing the commuting emissions from those employees? Can they take advantage of bus passes, carpooling or any other transportation benefits offered to regular staff? Clearly, if the work was not outsourced to Sodexo, the campus would have to hire in house dining service staff (whose commuting emissions would need to be counted for the Commitment).
Scope 3 issues are the throniest of all, but tracking them is the first step in hopefully reducing them in a meaningful way.

-Niles

Thank you for this response, Niles.  I am planning on moving forward with collecting this data and incorporating it into our carbon footprint.  The data is fairly easy to access and we can implement strategies that can influence this source of emissions. 

Thanks for responding, John