Well this is an odd topic, lol. But I must agree with Gnx here, regardless of technicality, they are for all practical means and purposes, female. They're anatomically correct, dress accordingly, and their personalities are all those typical of females and of course, they're capable of producing human offspring, it really doesn't get more female than that. It would be extremely pedantic to want to push a "gender-neutral" stance when the gems are very very clearly not gender neutral. There's little debate to be had, really. I wouldn't hold it past Sugar to deny it though, of course she must carry a level of mystique and intrigue about the Gems just as Ward was about the state of the Earth in Adventure Time before it all fell into place and thus, has to make sure what she says is all very technically correct without showing her hand, etc.

The fact that they're technically genderless is little more than a trivia point. After all, if a fictional character acts, looks, speaks and is anatomically described as female...than they're female, and the technicality has little to no impact on anything.

It was actually confirmed by a Steven Universe storyboarder that Gems do not have any internal organs unless they create them via shapeshifting.

Gems have no biological gender, regardless of how they look or dress. It's just a coincidence that the Gems we've seen so far choose to identify as female (Other than Steven, who is the first Gem to have a biological Gender and the first Male Gem in existence)

We've seen the gems carry out biological functions such as eat, circulate blood, cry, and vomit. Their bodies feel pain, and we've seen Pearl suffer serious injury when attacked in a vital spot. Any extension of their being beyond their gem likely counts as shape-shifting. Like I said, the bodies they choose to have, thus far, have been female by human standards, and they choose to identify themselves as such.

What exactly are you saying? Adventure Time has a COMPLETLY different storyline than Steven Universe, Ex: The Great Mushroom War. But Gems have the ability to eat even though its not a necessity, showing they do have digestive tracts. Gem probably make themselves look like a specific gender to at least let people assume they're male or female.

Pain is an understandable function for them to have, they need to know if their body is in danger of being destroyed.

Blushing would be as simple as altering the colour of their skin. It was stated that the Gems don't need to eat, meaning that they couldn't have a digestive system or any other organs that require nutrients. It was implied that Gems don't need to breathe by Lapis Lazuli who left Earth to travel through space and by Pearl when she only mentioned that Steven would need a space helmet to not suffocate in space.

When Pearl was stabbed, if she had internal organs and blood, she would have bled. Instead she just froze up for a few seconds before she calmly tried to assure Steven everything was going to be okay, then released her physical body.

The Gems don't have any organ unless they want to, i'm sure they can conjure one up at any time.

Where did she say that it's likely that the genders will be revealed in S.2?

Pain requires nerve-endings. While they don't need to eat, they are able to if they want, and can even get sick and vomit from certain foods, so yes, they do have digestive systems. Blushing is indicative of blood. Pearl had to retreat into her gem because her internal organs were damaged, and she was clearly in pain from it. She didn't have a chance to bleed because the blade wasn't removed. Granted, the things you're saying are possible, but the fact that they simply take on a human anatomy when taking a physical form beyond their gem is the likeliest explanation.

There aren't supposed to be gorey scenes in cartoons, explaining why Pearl didn't bleed. When Gems holo-projected bodies are mortally wounded, they retreat to their gems to regenerate any injured insides, Ex: When Pearl was stabbed in the gut, she possibly had to regenerate a heart. And in Coach Steven, Pearl demonstrates that Gems can generate blood. Plus, Gems wouldn't be able to move without muscles or nerves.        

On the Adventure Time thing, they're not saying the universes are connected, they're saying that Rebecca and Ward's artistic and narrative choices are similar. 

Ok.