I think Octave only return one value which is the first return value, in your case, 'array'.
And Octave print it as "ans".
Others, 'listp','freep' were not printed.
Because it showed up within the function.
Try this out:
[ A, B, C] = initialize( 4 )
And the 'array','listp','freep' will print as A, B and C.