The article you linked to does not mention at any point that LBS is a mass, or at all uses the word mass at any point throughout. In fact, it breifly at the end mentions "1 lb=0.45359237 kilogram" as well as "1 Newton=0.224809 pound force" which could indicate a difference between LBF and LBM distinctions.
It's commonly understood that you will weigh a different amount of lbs on the moon than on earth. Because it isn't a mass. It's a force of gravity.
There is also evidence in the form of lbs/in^2 being a common measurement, which would be completely nonsense in the context of mass.