One problem is that many will get used to wear a mask emotionally. Subconsciously you are in hiding and can act a bit more anonymously (More so than sunglasses).
This will be hard for some to give up when that time comes, they will feel naked and vulnerable without it, and however they will deceive themselves to avoid that truth will be seen in what will be the most usual excuses for still wearing it.
/PsychAnon