I've read the article and the linked papers, and IMO this stems from a huge misunderstanding on what "insert" is, given inserts in DNA and RNA sequences can occ

I've read the article and the linked papers, and IMO this stems from a huge misunderstanding on what "insert" is, given inserts in DNA and RNA sequences can occur with replication errors and then can be kept due to selective pressure. So, that can't prove or disprove what this person is saying. The part with the "previous version" of the paper is also fishy, given that it is not shown.