Yes. Mungia is not elite. GGG even way past his prime still knocks him out. Mungia is exactly like the kind of guy GGG used to toy with back in the days.
Mungia has below average defense. G is accurate, hits just as hard and has a better chin. Good fight.
Munguia has gotten better since this fight was first proposed and GGG has slowed down more. I think Golovkin still wins but he may have to work for it now.