Regarding Megan's claims, I've been saying this for two years, ever since I learned what the "95" in "N95" stands for. I was just too lazy to do the math! But the N95 wasn't made for, nor is it rated for, the prevention of the transmission of airborne viruses. Megan's numbers are actually conservative, because she's considering the N95 masks to be 95% effective at stopping the passage of the SARS-CoV-2 virus, when it is almost certain that it is, in practice, much less effective. The conservative numbers, however, are good enough to prove her point.

Concerning COVID-positive individuals sharing enclosed spaces, remember that asymptomatic transmission is unknown. So unless these "positive" individuals are symptomatic, they pose pretty much zero threat to anyone else on the aircraft.