That would be true and I would agree with you. But in this particular case the vibranium origin isn't happening . It's simply being used in a story. It was always a special space metal so while a few are getting up in arms because BP wasn't in the story or mentioned they are failing to consider that the metal Vibranium could very well be prevalent on a few planets. Which in return only opens up BP world.
But hey getting mad and stirng up fans is the popular thing to do on the internet so let's just keep doing that. Lol