Amazon's Graviton ARM Neoverse CPUs only implement ARM NEON SIMD rather than the newer SVE2. I don't know if ARM SVE2 has Matrix math instructions like AMX does. Intel AVX++ might be an important alternative to discreet ML/DL accelerators. DL Training accelerators appear to be focused on RDMA Over Converged Ethernet [1] (RoCE) and I'm assuming that this technology is new enough for Intel to gain a foothold.
I don't know if I understand this space well enough but I think there are enough truths in this explanations to keep me from ruling out Intel.
[1] https://en.wikipedia.org/wiki/RDMA_over_Converged_Ethernet