1. The driving force behind the original accusations is that Magnus felt his opponent wasn't "exerting" himself enough, compared to other young prodigies.
2. Chess.com's case is that his results are "statistically extraordinary."
3. There is a history of cheating
4. Allegations that he admitted cheating privately (though it's not clear to whom)
1, 2, and 3 could easily be cause for suspicion; however, that's not the same as evidence. The one crucial piece absent from this article is any suggestion of how he cheated.
Without providing a means, I find this piece premature and questionable. That said, I don't know anything about chess, lot alone cheating at the master level. So maybe the "how" is common sense and not difficult?
And of course, there's also this:
> The report also addresses the relationship during the saga between Carlsen and Chess.com, which is buying Carlsen’s “Play Magnus” app for nearly $83 million.