Data about allergic reaction rates, infection rates, and conditions that are ideal for spreading COVID are all public and not in dispute. My argument is a straightforward application of that data to the facts.
At the time COVID data was sparse and masks were seeing a shortage so that healthcare workers could not get enough to perform their duties. Was this the correct action, perhaps and perhaps not. You may also be correct with your conclusion but your recommendation is not been vetted by healthcare professionals and so there may be very large gaps in your knowledge (unknown unknowns) that make your conclusion seem like a no brainer to you.
Perhaps what you can do is take down the post and share it with a professional to see if it makes sense and if are any issues they see.
Lastly, medical advice comes with legal implications if someone follows it and comes to harm. You may be opening yourself to legal risk.
I know you've got the absolute best intentions, but it's our responsibility in this age of tech to be rigorous with truth and what we choose to broadcast to others.
The Surgeon General happens to be a pretty easy example, but there are many, many others, at every level of US government.
Its an interesting thought but be careful urging everyone else to avoid the recommendation.