Lassus published two sets of bicinia in 1577. The first set of fifteen of these are texted, another with twelve are not. Among the texted duets, numbers 6 and 15 use the same text, "Esurientes implevit. . ." [KJV: "He hath filled the hungry with good things; and the rich he hath sent empty away," Luke 1:53; from the Magnificat]. I am not an expert in 16th century text painting and will not comment on that element. Which is another way of saying that I don't see anything obvious in the particular choices of figures or cadence types.
The opening and closing measures are in the example below. The points of interest here are that Lassus is not afraid to use the 6-8 cadence to close (that is, he shows no prejudice in favor of 3-1), and the overall gesture in the upper voice is rising.