I've never paid for an article before. So it can't be paywalled.
My claim? It's straight from the author. Want to so this one by one? Here is the first one for you to break down straight from the source.
Maybe they allow a certain number of articles for free, but it wont let me read beyond the first couple paragraphs without an account.
From what I read, it does not seem like your claim is the same as the author's, but authors of articles on the internet are certainly not infallible either.
I don't have much interest in going through cherry picked portions one by one, but for the record, having a lower than usual but still slightly positive expected goal share through a half season of difficult minutes while still having a dominant goal share is not the end of the world you treat it as. While he had some struggles in the first half of the season, the referenced drop-off is not even occurring in his regular minutes. The Knies-Matthews-Marner line is at almost 56% xGF%.