If I recall correctly, when the search was abandoned, it was to take advantage of superior underwater technology that would become available. Commissioning same would not be instantaneous, and given that availability, it apparently seemed prudent to release some of the equipment being used to tasks and users who had been pre-empted for the search.
From the look of it, two things happened: First, additional analysis of sonar records (with more sophisticated signal processing), on land, revealed a very likely place to begin the new search, and secondly, the enhanced subs were able to complete their
mission efficiently.
But I guess that some didn't really read the whole record.