On one hand, normal GPU mining is practically never efficient with respect to the cost of electricity. Even in a hyper-efficient datacenter, Bitcoin mining is now dominated by thousands of ASIC miners who are running hardware a hundredth the cost of GPUs at 10x+ performance.

But on the other hand, these machines aren't just sitting there powered off when they aren't provisioned. They have to keep them warm so they provision ultra quick.

So maybe there is some level of mining they could accomplish with their "idle" cycles, given the efficiency of the datacenter, the power of their GPUs, and the price of Bitcoin, which would be profitable. I don't know.