Hmm it's quite hard to confirm if you the person herself doesn't confirm it. We can always send her a tweet, but we don't know if she'll respond. The person who owns the account may be 96neko herself or she may not, but i believe it's a fan impersonating 96neko.
I've done a little research based on the link you've provided. If you go down to the journal history, you'll see an interesting topic. "Curious about how vipTenchou looks?" If you click the link it shows a picture. However if you take a look at the link it was uploaded by the user "Manga-kaMaster" Which doesn't seem like a "legit" kuroneko username. I'm not saying it's impossible though, because it's not.
Take a look at his/her account: http://s1284.photobucket.com/user/Manga-kaMaster/library/?sort=3&page=1 If you flip to the second page, it seems he/her has quite an abundance of legit selfies or photos taken of 96neko.
What i find strange however is about vipTenchou. There is no information (or that i know of), about 96neko and vipTenchou having connections in real life nor do we know how vipTenchou looks like in real life. According to the spanish wikia, http://es.utaite.wikia.com/wiki/Vip:_Tenchou he looks like so. I believe i've come across this photo before in this wiki, however it was not put under the name vipTenchou. Here are some photos i believe are valid: http://25.media.tumblr.com/365d4cd38c64ea575081b36a991503a1/tumblr_mor6d0Od6i1rmkef5o2_400.jpg http://24.media.tumblr.com/1efd062e97b361897534edc78f498c82/tumblr_mor6d0Od6i1rmkef5o3_500.jpg http://24.media.tumblr.com/57ed0d2db01f652709aeafe451891258/tumblr_mor6d0Od6i1rmkef5o4_400.jpg
Not so sure about this one but here goes: http://25.media.tumblr.com/d7c12176eaf4b4da7579c49748d35227/tumblr_mor6d0Od6i1rmkef5o5_1280.jpg
Another thing i can say is the "friends" list sort of gives it away. Take a look at it yourself.
Some things to note about: Deviantart isn't a popular japanese site; under about it says she's an official beta tester; although this is only purely hypothetical this account was created 3 months ago and has no premium membership, the majority of impersonators do not pay for their accounts; I've been following her twitter account for a while now and she always starts her tweets with "【定期】", "【96猫オフィシャルファンブック】" or "【96猫情報bot】".
^ Seems like she's/he's purposely trying to degrade his/her english, right?
Well that's about it from me... it's alot easier to just ask the person herself. Sorry for posting such a long reply... （・□・；）
What do you think?