That's not a spin off if Intel fully controls it. That's the arrangement Samsung has with its foundry, and when Jobs was pissed at Samsung's mobile division that fake on paper separation didn't stop him from taking Apple's business to TSMC. Apple is responsible for 25% of TSMC's revenue - having Apple would probably double or triple Samsung's foundry revenue, so that organizational decision ended up having HUGE consequences!
Do you really think Intel could ever win AMD's business with such a Chinese wall arrangement? If Intel starts competing with GPU/AI for real would Nvidia be willing to consider them? Would Apple truly trust putting all their eggs into Intel's basket if they don't believe those in-house x86 CPUs won't get preferential treatment when wafers are scarce?
No, I think when it is spun off it is really spun off, with Intel's shareholders receiving an equivalent stake in the new company which then trades under its own ticker and operates under its own management. It won't even have "Intel" in the name.