"Never attribute to malice that which is adequately explained by stupidity".
More likely explanation is that Amazon is using a third-party to provide candidate emails from LinkedIn profiles and using that to do proactive reach outs. That third-party is scraping emails from all sources, including HN and providing that as a service to Big companies. Some recruiter at Amazon decided to do an email blast using some generic query based on keywords and got your profile included. QED.
More likely explanation is that Amazon is using a third-party to provide candidate emails from LinkedIn profiles and using that to do proactive reach outs. That third-party is scraping emails from all sources, including HN and providing that as a service to Big companies. Some recruiter at Amazon decided to do an email blast using some generic query based on keywords and got your profile included. QED.