We've been living in that world since the invention of the compiler ("automatic programming"). Few people write machine code any more. If you think of LLMs as a new variety of compiler, a lot of their shortcomings are easier to describe.
Likewise, many optimization techniques involve some randomness, whether it's approximating an NP-thorny subproblem, or using PGO guided by statistical sampling. People might disable those in pursuit of reproducible builds, but no one would claim that enabling those features makes GCC or LLVM no longer a compiler. So nondeterminism isn't really the distinguishing factor either.