It would be unlikely that anyone would/could share public details about such a thing given the NDA (and potentially LOI) terms that are signed prior to something like this happening. It happens though.
Yeah. A small company I used to work for had a phase where Amazon contacted us and wanted to potentially partner up. CEO went and spoke at Amazon and they got to see our goodies and then nothing came of it.
I think that their intention was to duplicate what we were doing if they got on the other side and thought it was valuable.
Turns out the company was/is floating on investor money like so many startup ponzi schemes. I suspect Amazon just didn't think it was worth it.