Netflix is probably using emails from 500px's data breach for email marketing

I've been using username+secondarykeyword@gmail.com trick for quite some time.

Earlier this year, I started getting weird emails from Netflix. They're weird because I'm already an active Netflix subscriber, but the emails are for inviting me to join Netflix.

When I took a closer look, I noticed that the email was for username+500px@gmail.com

Screenshot: https://i.imgur.com/wG0IhUK.png

I only ever use that email for registering with 500px. I'm also aware that 500px experienced a data breach on 2018.

So I'm highly suspicious that Netflix is using emails info from other websites' data breach for marketing purposes (knowingly or not).

This is very worrying, IMO.