They are acting, roleplaying out a situation where this place is real.
It is a bit of fun and is not to be taken seriously, this place doesn't have a location and it doesn't have a phone number, in reality this facebook page is most probably run out of a home or office, not a magickal university in the world of a TV show.
Think about it, it is a fantasy TV show, it is not real , much like you cannot go to Mystic falls and meet the vampires from The Vampire Diaries and Buffy the Vampire Slayer was not a documentary.
Everything is done to draw your attention to it, just like Harry Potter has Pottermore where you can be sorted into your house, this website has an entrance exam you can take, just as Harry potter is not real, this isn't either. Everything they are doing is to keep your attention before the net season it is great advertisement.