No, that is not a program emitting to output stream "hello, world!"

It emits "{Hello, world!}" which is like emitting "func main() { print("hello, world!" } }"

A hello, world for this language would take "hello, world" as an operand to some operator that spits out strings. That example is not there.

If you read the description the language outputs programs. If it would be able to output any string, it wouldn't be concanative language anymore.