It would seem officialdom was well aware of the actual risk posed by CV19 well before the lockdown.
Fauci (the chief US medical adviser on CV19 and a regular speaker during the US President's Press conferences) wrote in an editorial published in the prestigious New England Journal of Medicine (February 28, 2020):
On the basis of a case definition requiring a diagnosis of pneumonia, the currently reported case fatality rate is approximately 2%.4 In another article in the Journal, Guan et al.5 report mortality of 1.4% among 1099 patients with laboratory-confirmed Covid-19; these patients had a wide spectrum of disease severity. If one assumes that the number of asymptomatic or minimally symptomatic cases is several times as high as the number of reported cases, the case fatality rate may be considerably less than 1%. This suggests that the overall clinical consequences of Covid-19 may ultimately be more akin to those of a severe seasonal influenza (which has a case fatality rate of approximately 0.1%) or a pandemic influenza (similar to those in 1957 and 1968) rather than a disease similar to SARS or MERS, which have had case fatality rates of 9 to 10% and 36%, respectively.2 (source)
This is a particularly relevant clarification from the editorial because it cites two studies of note. Specifically these:
On the basis of a case definition requiring a diagnosis of pneumonia, the currently reported case fatality rate is approximately 2%.4 In another article in the Journal, Guan et al.5 report mortality of 1.4% among 1099 patients with laboratory-confirmed Covid-19; these patients had a wide spectrum of disease severity.
The first is important because taking a diagnosis of pneumonia as being essential for a case of CV19 to be diagnosed as such, means that an individual is actually suffering from serious symptoms (i.e. not just a dry cough, etc). Yet even amongst these cases, the fatality rate was 'only' approx 2%.
The second study cited is important because it is based on laboratory confirmed cases of CV19. Naturally, this is a very different situation compared with CV19 being diagnosed solely due to symptoms (e.g. again, by the presence of a dry cough). Further, in this study there were a significant number of subjects involved (1099) and so the data can be considered more reliable than if the findings were based on a smaller case number.
A second significant determination by officialdom, was in the UK by the HCID group On the 19th March, they published the following (my bolding):
Status of COVID-19
...
As of 19 March 2020, COVID-19 is no longer considered to be a high consequence infectious diseases (HCID) in the UK.
...
The 4 nations public health HCID group made an interim recommendation in January 2020 to classify COVID-19 as an HCID. This was based on consideration of the UK HCID criteria about the virus and the disease with information available during the early stages of the outbreak. Now that more is known about COVID-19, the public health bodies in the UK have reviewed the most up to date information about COVID-19 against the UK HCID criteria. They have determined that several features have now changed; in particular, more information is available about mortality rates (low overall), and there is now greater clinical awareness and a specific and sensitive laboratory test, the availability of which continues to increase.
...
The Advisory Committee on Dangerous Pathogens (ACDP) is also of the opinion that COVID-19 should no longer be classified as an HCID. (source)
Various apologists claim that such a downgrading was only made so as to allow for CV19 cases to be treated by more than the four main HCID hospitals in the UK. However, this seems somewhat disingenuous given the low overall fatality rate clearly mentioned. I mean that only a few days afterwards, the UK gov begin 'half frightening-to-death' the UK population. Imo, the propaganda was such that it gave the impression that any of us would be lucky to still be amongst the living in only a few weeks henceforth.