To quote the "article":

While the IP protection feature might enhance user privacy, the tech giant has clarified that it is not a foolproof system. If a hacker is able to gain access to Google’s proxy server, they will be able to analyse all traffic passing through the network and even redirect users to malicious websites.

This means that if a hacker can do this, then obviously the same goes for Google itself. Google will analyse all your online traffic data and use it for themselves. This isn't pro privacy, it's the complete opposite.