Apple surely doesn’t have a cluster that at all compares with the big cloud giants.
Oracle and AWS are really the only cloud left, and oracle is already renting to Microsoft for GPU compute.
Apple has a lot of cash to throw at it. Question would be if Apple is even interested in it.
The best they can do is out-bid their competitors, for the competitors hardware. I'm sure apple doesn't want to pay Google for GCP resource to train an AI. Again, there may not be enough companies renting out GPUs at all.