From the wording of the article
> The requested documents – more than 50 years old – should be unclassified and releasable by now under federal declassification rules
...
> “The plaintiff believes this document review is overly complex,” Eatinger said during the hearing. “When we filed this case, the records were in an automatic 50-year review project. We were told it would be complete in May 2019.”
these are (or should be) formerly classified documents. The Navy seems to be dragging its feet with the mandatory declassification review. As Eatinger said, it is well past time that the review should have completed and de- or re-classified as appropriate.