Weird story. Bet that someone is lying about something.
Yeah, some details are missing at the very least.
IIRC, there were hysterical, arm-waving articles last summer about mass graves being used on Hart Island (NYC's "Potter's Field"). I assume that these corpses would've been buried there long ago if they were unidentified, unclaimed or next-of-kin was unknown.
The likelihood is then, that the corpses in the mobile morgue *were* identified... but apparently remain unclaimed. New Yorkers are apparently willing to let the state bury their dead family members in numbered graves, as long as it's free.