You don’t need a new IP just to include gay characters.

What you do need is competent writing. The issue with this isn’t that there’s something wrong with two main characters who happen to be the same gender being in a relationship, it’s that there’s something wrong with shoehorning in a relationship (genders irrelevant) among established characters, where none existed before, just for the point of making a “statement”.

MLP is not a show about romance, it is a show about friendship. You can have romances in the background without upsetting this, even concentrate on them for an episode or so, but a foreground romance would be almost impossible to write without it taking away from the show’s primary purpose of exploring what it means to be, and have, friends.

1. Whitley is mostly talking big to try and impress his twitter followers. Personally I’d be much more impressed if he ever introduce an unambiguously gay character to the comic. Until then he is much a collaborator in the stuff he complain about as anyone else working on the show.  
2. That being said the reaction I saw here (especially on the other picture… that was uploaded without drama tag as well) play right to his hands.  
3. Just when you think stuff can’t get any worse, Here comes murrison.
    
   As for the whole having some established characters come out as gay, so far the main six with the exception of rarity and twilight (in EQG) are more likely to be ace than straight. We actually don’t know what most of the shows characters sexuality is. Because of this I literally can’t care any less about any individual charter’s sexual preference, the show will just ignore it most of the time and us fans will just keep assuming that everyone is bi.
    
   On the large scale of things, I’m mostly sad that romantic and sexual orientations are so tied up with politics at the moment. I can assure you that the top brass at Hasbro have already had the meeting where they discussed adding gay representation to the show for the positive coverage it would give them, and decided that the backlash from conservatives just isn’t worth the hassle.

“childhood friend romance that’s been subtly growing for six seasons”