[TangoLimaSierra]

They're talking about one thing and ignoring that any change to the moon's mass will affect its orbit.

You think we will pile enough mass to alter the orbit of the moon? Seriously doubt it.
Anyway, since the moon is gradually moving away from us, maybe a little more mass would help keep it around.

[T.B. Yoits]

You think we will pile enough mass to alter the orbit of the moon? Seriously doubt it.

Any mass will affect its orbit. It's current mass has been altered by asteroids, comets, and meteoroids but who knows what "straw will break the camel's back"?