Channel count 96 refers to mixing channels inside the DM2000, not the number of inputs/outputs.
AFAIK DM2000 has 6 slots which means you CAN have 96 channels of MADI I/O. And you also have 28 analog inputs and 4 channels of AES/EBU inputs, which makes it possible to fill all those 96 channels even with only 4 MADI cards.