Because Linux distributions must contain the Linux kernel, which is built with the assistance of AI tooling.

It does have very strict standards, but AI is explicitly allowed to be used in the aid of development of the Linux kernel.

You can't be hard-no-AI as a Linux distribution because it would be like having a vegan car company where the seat supplier used leather. You'd have to fork the Linux kernel from the last version that was developed before LLMs were adopted, or write your own kernel.