Hmm there is a difference between that kind of denial and this type of whitewashing by China for me at least.
Putin/Russia denies that Ukraine/Belarus as a state existed. Their version of why it doesn't exist is different from the objective or the opposing side. But their denial is open and more or less have always been denying it. Like Taiwan/China, they claim TW is theirs and more or less have always claimed this. Their version of historical events is always a version (not always the same version) that will support their claim. The textbooks say the social unrest was a threat to national security and external forces were behind it but that is what the HK gov have said every day for the last 3 years! Why wouldn't the HK's textbooks say the same. For these sort of differences, there is no need for the friend protocol, I will just voice my opinion and we can argue openly.
It's the other kind of whitewashing e.g. We fired UN - UN didn't fire HK, HK was never really a British colony because the treaty is unfair and should be void - the type that photoshops their past actions because it was less than above board. It doesn't just omit the detail, it will actively put out a version where they're the good guys. This is the kind of whitewashing that happens when there's a pathetic insecure, scheming conniving weasel somewhere in there - wherever it came from. Too pathetic to accept themselves for what they are and too insecure to not care about other ppl's opinion and too weaselly to improve organically.