They certainly were spreading it on purpose. What's unknown is whether they knew it was misinformation at the time. Perhaps they thought this was a good way to manage supply shocks and keep masks flowing to medical workers. Or perhaps they truly thought masks were useless. That's hard to believe, but not impossible.

But they wouldn't have backed off as quickly without pushback from others taking the opposite position that masks were critical. And at the time, that was contrary to the officially espoused position by both CDC and WHO. Even now WHO haven't fully reversed course, they have only stopped anti-recommending face masks as hard. Banning spreading this countervailing opinion would have been a grave mistake.

WHO: https://www.who.int/emergencies/diseases/novel-coronavirus-2...

> If you are healthy, you only need to wear a mask if you are taking care of a person with COVID-19.

CDC: https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-si...

> In light of this new evidence, CDC recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies) especially in areas of significant community-based transmission.