Thanks, I remember this article, though it is quite out of date. Monero has 3 distinct privacy layers protecting sender, amount, and receiver. Admittedly, sender privacy has always been the relatively weakest part in Monero and vulnerable to these statistical attacks. Like the article says, this attack only effects senders (an adversary can potentially know you sent monero, but not how much or to who). It also brings up Central Exchange transactions being traceable, but of course they are, that has nothing to do with Monero. Even though ring signatures have been robust enough in practice so far (to date no one has ever been busted because of ring signatures) Seraphis upgrade will make sender privacy much better with full membership proofs.