On February 5th, 2019, Tesla appeared to do a soft launch on Amazon. The site quickly got hammered with attention and sold out of everything (or inventory removed). Shortly after that the page was taken down.
Today I found out that they relaunched the Amazon Tesla Storefront. Everything appears to be stocked as of this writing and prices match their Tesla.com store.
I speculate this is a step to utilize Amazon's distribution and logistics while allowing Tesla to focus on more important things, like building cars.