There are innumerable descriptions and definitions of theistic evolution. How things are phrased matters a lot.
It’s ABD — “Anything But Design,” as Sarah Chaffee says — that is, anything but design that might leave open the door to a source of transcendent intelligence.
In 1929, child psychologist Jean Piaget called children “artificialists” who tend to regard everything as “the product of human creation.”
Complexity (such as we see in a pile of autumn leaves) can arise spontaneously from unguided natural processes, but complex specified information cannot.
This is one key issue on which proponents of ID and of theistic evolution differ.