I feel traditional "rust" hard disks would be inefficient for AI use. Unless they include SSDs (which I feel these data centers are more likely to be using) in the definition as well...
In a large rack-mount SAN with hundreds or thousands of disks connected to your computing equipment via fiberchannel, the performance difference is pretty negligible.
The real advantage of SSDs in this use case is storage density and power efficiency. On the other hand, your compute resources might be packed in so tight with power-intensive stuff that you appreciate the spinning rust “wasting” space.
