amethyst/bismuth theory

So, we know that Amethyst’s form is different in the clip with Bismuth, so she probably got poofed. Bismuth doesn’t know anything that happened after the war, and Amethyst hadn’t joined the crystal gems or even existed until after the war. So, Bismuth might’ve assumed she was an enemy gem and poofed her.

Even with Amethyst’s stars, she and Bismuth would have no way to have known each other, however it was implied Bismuth knew Pearl and Garnet. So Amethyst’s stars would be irrelevant or not enough to convince Bismuth she wasn’t an enemy.