I believe the message remains for 30-days after it has been triggered, but I will have to do a bit more reading/research before I can say definitively.
This is true, it is the same if user change e-mail or password as warning to other users that they should be careful when dealing with such users if account is change owner (sold account)
Don't know how much time the warning is shown if a user changes email but if a user changes its password, the warning shows less than 1 month (I am sure), although I am not sure how much time exactly it shows the warning. I think it's not more than one week.
Edit-a password change will be shown for 3 days.
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