IoT devices are already getting owned at staggering rates. Adding a learning model that currently cannot be secured is absolutely going to happen, and going to cause a whole new large batch of breaches.
A processor that isn't Turing complete isn't a security problem like the TPM you referenced. A TPM includes a CPU. If a processor is Turing complete it's called a CPU.
Is it Turing complete? I don't know. I haven't seen block diagrams that show the computational units have their own cpu.
CPUs also have co processer to speed up floating point operations. That doesn't necessarily make it a security problem.