I still don't understand why it needs to be a requirement.
Why do you even want to "reach out to me"?
If I don't subsribe to project updates with projects that I support, why would I want you to "spread the word about projects" that I probably don't care about directly via email?
That's exactly why I was hesitating giving it to you, I simply don't want to receive your newsletter, random project information or whatever you might send.
And why give it to you just to later opt-out or not subscribe (if users really have that choice)?
Sovereign email providers don't change anything, as mentioned before, it's less about me hiding my mail, as it is about you not needing it, except for filling my spam-folder.