I don't think it has to be sustainable. They just need more time for EPYC to really take off and for Ryzen to continue gaining market share. I think their strongest areas are going to be CPUs and APUs, and things like Kaby Lake G. They shouldn't give up on graphics but it's going to take longer for them to be super competitive there.

If it gives them the capital to start seriously competing in deep learning, then it doesn't matter.

If anything, (having assumed they also know the crypto position might not be sustainable) it's better that it's not. Hopefully that means enforced innovation from them for future products, bank the cash now and invest in newer tech for the future.