Used APPLE ID to log onto an app

So I used APPLE ID to log onto an app and got a pop up saying, if I wanted to share my email with the app, and I said NO, and two minutes later, I get an email from the company saying do I want to buy the APP.

With privacy laws being reviewed by APPLE and they saying my email was not going to be shared, can someone from apple contact me, . As this is a direct violation of privacy laws .. what is all this about. Can someone explain to me.

Thank you