What makes you think this is special treatment? In fact, this gives us more room to link the actual homepage and blog of the artist in question.
Uh, what? There's an explicit "Pixiv ID" field in the artist page. That's special treatment.
You can specify multiple URLs now, too (you can see what it looks like on http://moe.imouto.org/artist/add, which is running it already), which seems to make this particularly unnecessary.