I'm responding to the paper you linked, where you assert "this has happened before".

The story with the Reddit link is similar: at the time of the posting, only ~6 data points actually mattered for R^2, so you would expect R^2 to be very high. (The fit is extremely poor for the first ~6 data points, but that doesn't affect R^2 at all.) After the last date on the chart shown, the R^2 begins to plummet. This is also exactly what you would generically expect.

Amusingly, both of these totally ordinary results are taken as evidence for a conspiracy: the 6 points that fit are taken to be fabricated, and the subsequent points are taken to be fabricated with the sole purpose of throwing off people on Reddit. But if you can claim evidence for a conspiracy no matter what the numbers are, has something gone wrong in your reasoning process? You be the judge!

I would say the numbers deviating from the model after it has been publicized and discussed online are still evidence against the data being fabricated, but weaker than it could have been because there were definitely Chinese people watching those discussion on social media, and so the idea that they might have corrected the mistake and started adding more variation isn't that unlikely.

wow you make it sound like someone is sitting in front of a computer, watching reaction of foreigners on reddit, and tweaking the numbers on an excel sheet. Really? You know, Chinese ppl online really hoped it wasnt a quadratic curve. If the government was just making up the numbers and trying to hide the problem, why not make it linear, or square root? why pick quadratic, such terrifying curve...why say its cornavirus at all? just say its flu, its pneumonia, its a terrible flu season. If all the government cares about is money and economy, why shut down the cities at all and destroy the economy in the processes. When economy is down, business will go bankrupt, people will be pissed, and maybe they will revolt. Why go through all this trouble and not deflect the issue or take no responsibility at all. Isn't all about protecting people and keep people from getting sick? oh btw, now that model doesnt fit anymore, the reported number is higher than the predicted model

I have no doubt there are Chinese propagandists sitting in front of computers watching and interacting with foreigners. I don't know why you think that idea is so ridiculous. The west does it, why wouldn't China?

You're asking a bunch of unrelated questions. It's pretty obvious the epidemic in China is very serious. That's why they are taking all those measures.