Don't they need gpus (for training)? Apple already did a footshoot wrt gpus in the apple ecosystem. unless they have some sort of apple-internal ai chips ready to train models.
Apple has no interconnect technology comparable to what Nvidia ships to datacenters. The larger Nvidia clusters measure their addressable memory in terabytes, the value of Unified Memory at that scale is practically negligible (if not wasted bandwidth).
You're making some pretty handwavy generalizations here without a solid grasp on why Nvidia dominates GPGPU compute.