A properly used and fitted N100 or P100 respirator will, by definition, protect the user from infection through inhalation. If we're resorting to making guesses

A properly used and fitted N100 or P100 respirator will, by definition, protect the user from infection through inhalation. If we're resorting to making guesses about infection profiles, intuition says these types of users have probably not picked up an infection through other means. Forcing them to downgrade to inferior masks probably puts others at a higher risk...