@Equestria Girls Rumour
I can think of one way it may work, but the chances of it being that way is… Minuscule.
As mentioned previously, they'd have to in some extent still resemble ponies, even if it's anthro ponies. Otherwise it's either pointless or ugly.
Then, second, it would have to be more fantasy/action oriented. This is mainly because they'd be taken out of their normal world, and it's hard to keep that up without more action to prop it up. Adventure and all… There's also the fact that your talking teen demographic.
Third… And this is the most important part… It can't just be a caracture of teen girl life.
I'm not familiar with life as a teen girl, or a teen guy for that matter due to having been stranded in the middle of nowhere for most of my childhood… But if I was familiar with it, chances are there'd be relatively little shopping, that stuff hasn't been true in years. More interestingly, most girls I actually interacted with were more interested in anime than clothes. With one being a fan of Death Note and Black Cat.
In fact, I'm begining to suspect the image of girls being Shopping obsessed socialites is a constructed image that was never true in the first place.
I'm sure there's a couple of things they could do for the concept, but so far… I'm coming up blank on things that they wouldn't be able to do in Equestria.
Not to mention… I'm pretty sure they shouldn't be in high school for the expressed fact they are all already out of Highschool from what we know… You know, at most, all they could do is go to get a diploma, and so far, I doubt any of the main 6 but Twilight Sparkle would bother.
So yeah, the idea, as we have been led to believe, is not that great.
… But… That simply makes me have to note… That it's quite possible we're missing something here… Like what's been leaked is glaring over some detail that may change everything… Might be nothing though.
Edit: something random just happened… Some girl's phone just rang using Rainbow Dash's Voice. Not sure if I should say something.