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.
Government will now give families thousands for a covid funeral