I believed the exoatmospherics affected propagation and was not intended as of itself to destroy anything. You are right that constellations in sight of the burst would be toast. However this link
http://www.studycommittee.org/high-a...ear-tests.html it tells how satellites entering the burst area where also destroyed.
It is possible that improved techniques have been developed to harden the satellites.
http://stinet.dtic.mil/oai/oai?&verb...fier=ADA254944