No, the UB has NOT come to abolish anything! Think of it as when Jesus told his apostles that he had not come to destroy the Old Testament, but to FULFILL the covenant of the olden prophets!
So, the UB is an enlargement and some correction of what is in the Bible! For example: the NT in the BIBLE covers 28 days of Jesus' life, whereas the UB covers his WHOLE life...
For those who are sincerely asking about Jesus - which do you think they would like to study?!