Answer:
The MAX16020 exposed pad (EP) pad is electrically connected to the die substrate with conductive silver epoxy, and internally biased at ground. The EP can either be left unconnected (floating) or connected to ground. Connecting to ground is recommended as it allows low thermal impedance from the junction to the copper ground plane.
The MAX16016 pin description table on Page 9 omitted the exposed pad connection, but it is best to follow the recommendation provided in the same datasheet for the companion MAX16020/MAX16021 devices:
"Exposed Pad. Internally connected to GND. Connect EP to a large ground plane to aid
heat dissipation. Do not use EP as the only ground connection for the device."