This section is similar to many others we see in Jeremiah as God speaks doom over his rebellious people. I have some somewhat original thoughts on the possible meanings importance of Babylon being described as an ancient nation and nation whose language you do not know. In addition to simply teaching the fear of the Lord, I think there's a good lesson to be learned here about the way human nature is bent towards serving and worshiping something. The human heart cannot survive without something to serve, and if it's not God, you will put something else in that place, and God will repay you for your choices. Like I say in the thumbnail, play pagan games, win pagan prizes.