I think you are right, and that is why I was pleased by the authors of the article, who assert that (assuming masking is effective at preventing people from getting highly transmissible but less virulent strains of the virus) it is a bad idea because it might lead to antigenic shift to a more virulent strain of the virus.

There's an obvious argument about not masking because it is ineffective; I was glad to see someone cogently arguing not doing it even if-- especially if-- it IS effective. Esp. because this argument also works for all other countermeasures employed thus far.