The paper by itself is questionable. It's apparently peer reviewed, but no journal is willing to publish it for now. One author asked for their name to be removed while others reviewers have dismissed its authenticity.
It comes across as six of one and half a dozen of another. Either way, it's politically controversial if it's remotely true.
I would hesitate nowadays to call the UK's Telegraph titles (Daily and Sunday) credible news sources; both have been going downhill since their acquisition in 2004 by the Barclay Brothers. Many fine journalists felt their standards so compromised under the Barclay regime that they quit. One prominent resignation was that of Peter Oborne in 2015; see his personal statement [1] and BBC article [2].
(Disclosure: I was a journalist for the Telegraph Group for seven years until 2001, when I left to take a senior position at an online financial news and share-trading start-up. I remain in contact with many former colleagues from the Telegraph and other Fleet Street titles.]
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.
Now he read a paper and his credentials are used to 'spread the word' again.
Apparently they think it works every time.
In the meantime the virus has been under extraordinary genetic scrutiny and everyone else think that it looks perfectly natural.