Given enough time (and you did say far future) then theoretically, yes, the moon could grow as its gravity well gathers space debris. It certainly has been bombarded in the past as the craters demonstrate. The problem, then, will be what happens to the moon's orbit around the Earth. As it grows larger in diameter and gains more mass and gravity, somethings going to change. Both worlds' orbits will be affected.
It can't grow large then what it is at present. Secondly we have already produced the module city (would be) and with in next twenty years a affluent class may have their houses on the moon. You will be surprised even some people have purchased or booked a piece of land on moon.