I suspect that was deliberate. DoW is the preferred nomenclature but DoD is still technically correct. The article is phrased in a way to imply that the author

I suspect that was deliberate. DoW is the preferred nomenclature but DoD is still technically correct. The article is phrased in a way to imply that the author would rather the publication maintain independence. It is probably the last time she will be permitted to say "department of defense".