After watching the new Steven Universe promo and reading a couple of other people’s theories, I’ve thought of one of my own.

If Pink Diamond’s size is due to her being defective, like Amethyst, this could be the reason why she didn’t have her own colony and soldiers, because the other Diamonds were hiding her away to keep her defectiveness a secret.

When Pink finally gets her colony, she has to shapeshift to a more Diamond appropriate size whenever she’s around her soldiers.

Once the rebellion starts, what if, with time, Pink started wondering why she has to hide her size? Rose Quartz’s army’s got defectives and off-colors, and they’re still holding their own against the Diamond’s forces.

She expresses to Yellow and/or White Diamond that she no longer wants to hide her defectiveness, and Yellow and/or White feel they have to destroy Pink before she reveals her defectiveness to her soldiers.

According to Yellow Diamond’s song, all gems, even Diamonds, have a specific role and job to fill. And a Diamond’s job is to be a strong and powerful leader. Besides, if Pink Diamond’s soldiers saw that their Diamond was defective, it would ultimately show that Rose Quartz’s side was right in their inclusion of off-colors.