This news article is a direct response to [this one], as posted [here] as a comment.
They had said before that they would continue to allow people to log in to deactivated accounts so that they can view their purchase history. I don't see it as farfetched that they wouldn't allow people to sign into their accounts at all, especially considering a tweet I got from $chix0r on Twitter, when I posted about seeing things in my deactivated account, along the lines of "You should be glad you can even log in to the account!"
I remember when my friend had his Skype account hijacked. After contacting Skype, they reset his email address on his account to the original, and reset his password. I don't see why deviantART cannot do the same, and put the account back if it were wrongly deactivated. I know that each login and post has an IP tied to it, so they should be able to tell