Typical ignorance of photograpy.
Those were not "exposed but unprocessed," as the article claims; the last photo shows the block of negatives, stuck together, with partial image visible on the top one. They'd been developed, fixed, and presumably dried before they got left behind as the crew evacuated to their ship. The silver image survived a century in the ice, but this says precisely nothing about how long unexposed film can be kept in a freezer without suffering excessive fog and/or loss of sensitivity.