This kind of black-listing of specific domains is, unfortunately, just a game of whack-a-mole that's very hard for defenders to win.
If they're seeing targeted phishing (which the article implies that they are), then the attackers will just observe the drop off in people following the links and move the phishing forms to another domain or service, making it very difficult for the admins to keep up.
Really addressing this kind of problem has to come down to a combination of awareness training and improved authentication techniques (i.e. move away from static username/password combinations)
If they're seeing targeted phishing (which the article implies that they are), then the attackers will just observe the drop off in people following the links and move the phishing forms to another domain or service, making it very difficult for the admins to keep up.
Really addressing this kind of problem has to come down to a combination of awareness training and improved authentication techniques (i.e. move away from static username/password combinations)