Not how I understand it, but I'm not a lawyer. The user that uses the script to generate the code can copyright the output and oop can copyright their script (and the output they themself generate). If it worked like you said, it would be trivial to write a script that generates all possible code by enumerating possible programs, then because the script will eventually generate your code, it's already copyrighted. This appear absurd to me.

Relevant: https://www.vice.com/en/article/musicians-algorithmically-generate-every-possible-melody-release-them-to-public-domain/

If the script copies chunks of code under the copyright of the original script writer, I typically see for those parts that the original owner keeps copyright of those chunks and usually license it in some way to the user. But the code from the user input part is still copyrightable by the user. And that's that last part that is most interesting for the copyright of AI works. I'm curious how the law will settle on that.

I'm open to counterarguments.

While nobody created neural nets and back propagation

I believe you're claiming that compiler authors own the software their compiler compiles which is clearly not true.

No way does op own the algorithmically created program based on user input