I've never had 'additional review' comment. Its either they reject me or approve me, which suits fine, at least you know where you stand then. If they reject you, it will depend on why. If its reused content, you have to remove every content that you copied from somewhere, yea its hard. Some channels with over 2000videos removed all remaining just 3 videos because they were demonetised for reused contents, same for 'repetitive'. Youtube is not straightforward with regards to what exactly and which videos and they wont tell you. But repetitive can be using same video titles, similar, description, some thumbnails etc. Its really vast. A very popular channel with over 2m subs removed all his videos because he was demonetised for 'repetitive' contents, and only had about 5 videos left. It sucks.
Additional review doesnt necesaarily mean they will never approve you. Maybe they just dont see why they should approve you YET....
so it wll be up to you to make changes, create quality contents, use your voice or some voice, dont upload same contents over and over ect. Then write them again and again to remind them that your channel is still pending review.