So your point about anonymous critique is somewhat true. It's actually a little more sophisticated than that. Critiques often come in the form of historical parallels. For example, rather than critiquing Xi for having a bunch of "yes" men, some high up official in the party lauded the achievements of Tang Taizong -- the second emperor of the Tang dynasty. He's generally considered an exemplary ruler but the other trait known about him is that he was open minded and sought out people who disagreed with him. China became very cosmopolitan under him and the silk road connected China to far away places (it's the inspiration for Xi's Belt and Road Initiative)
So in praising Tang Taizong, the official was critiquing Xi's inability to deal with differing opinions.
This isn't a new thing, BTW. Chinese scholar-officials have been doing this for ages. China has historically been a very authoritarian country and the same ideas applied then (kind of). This is one reason why historical Chinese officials were (ironically enough) criticized by the Communists for being backwards looking. Straight forward critique wasn't allowed during the imperial eras so they always had to find historical parallels to vail their critiques and advices.
So in praising Tang Taizong, the official was critiquing Xi's inability to deal with differing opinions.
This isn't a new thing, BTW. Chinese scholar-officials have been doing this for ages. China has historically been a very authoritarian country and the same ideas applied then (kind of). This is one reason why historical Chinese officials were (ironically enough) criticized by the Communists for being backwards looking. Straight forward critique wasn't allowed during the imperial eras so they always had to find historical parallels to vail their critiques and advices.