Everyone gets an item when a chest is opened. It tells you what you get when loot is revealed. For vinyls and such you may have to wait a bit or reload. You may have gotten parts/embers,
I've opened two myself and got crafting components and I've had around 5 or 6 people open chests and I've got crafting components every time. I'm guessing cosmetic items must have an insanely low drop chance.