The generated program is a random sequence of bytes that just happens to take the shape of a seemingly working program by accident. Such is the joy of code that causes UB. You cannot deduce anything from what happens when you execute a program with UB, since that act is by itself meaningless. You need to establish that your program has no UB before making any inference based on what you see the program do after it came out of the compiler.
Ralf Jung on Is read_volatile on uninitialized memory really undefined behavior?