I agree that all those who are showing "outrage" at the song have to find hidden meaning and "discern" what the word "chosen" means.
The bottom line is that the term "chosen" in the New Testament and in the Old Testament does not in any way suggest a reference to the Messiah or to the Savior.
Peter -- But ye are a chosen generation
Samuel -- And Samuel said to all the people, See ye him whom the Lord hath chosen, that there is none like him among all the people? (That is a reference to King Saul, not David). Samuel, the prophet, tells us the Lord chose Saul, just because Saul was a failure does not mean he was not chosen.
Matthew 20:16 -- So the last shall be first, and the first last: for many be called, but few chosen.
This is how God brings judgment on those who think they are the elites.
John 6:70. Jesus answered them, Have not I chosen you twelve, and one of you is a devil?
Being chosen does not preclude the possibility of being the devil. Satan also was chosen to do a job.
John 15:19 If ye were of the world, the world would love his own: but because ye are not of the world, but I have chosen you out of the world, therefore the world hateth you.
The world hating you is evidence that you have been chosen out of the world by the Lord. It is not proof, but being hated by the world is certainly one of the characteristics of those that are chosen.
Acts 9:15 But the Lord said unto him, Go thy way: for he is a chosen vessel unto me, to bear my name before the Gentiles, and kings, and the children of Israel:
This is referring to Saul of Tarsus who had come to arrest Christians and haul them off to prison. Saul of Tarsus who was consenting unto the death of Stephen. God can and does choose people we would never expect.
1 Corinthians 1:27 But God hath chosen the foolish things of the world to confound the wise; and God hath chosen the weak things of the world to confound the things which are mighty; 28 And base things of the world, and things which are despised, hath God chosen, yea, and things which are not, to bring to nought things that are:
From the lyrics that I read this is clearly her point in her song.