This isn't deanonymization, it is modifying and infiltrating nodes to then listen what is happening from naive users connecting to them.

There was never an expectation of privacy when you connect to servers outside your control with non-encrypted data. That is the reason why the article itself mentions that this isn't working when running your own node, as most people do.

This is the same thing as complaining that Monero is no longer anonymous because Windows is capturing screenshots and keyboard presses when you open the desktop app.

Monero remains anonymous by default.