yeah, I noticed what @glnarayanan described is the case.
This is what Substack does, too. I think the purpose it serves (having asked Substack Support about this at the time) is that paid members who unsubscribe to emails are still recognised and can still access premium content.
However, from what I remember on Substack someone who is a free subscriber and unsubscribes is removed from the email list automatically (and you can receive an alert of this & said member if you want, just like for a new subscriber who signs up).
So, the above would make sense for Ghost, too. The issue is I think free subscribers who unsubscribe on Ghost are’t removed from the system so I have no idea if they have unsubscribed or not.
However, I think you’re alright legally because I noticed that anyone who unsubscribes does not receive emails thereafter (sent through Ghost). The only issue is that you are thus forced to send emails through Ghost; I have Ghost connected to EmailOctopus via Zapier, and it doesn’t look like unsubscribes are recognised and thus ‘taken away’ from my EmailOctopus list.
Just like with Substack, I believe this is so that free subscribers can still return to the website and access content. (Ghost also have ‘free subscriber-only’ content). However, I think my preference would be to have them removed from the database and have to re-sign up if they wish to. If a free subscriber has unsubscribed, chances are they won’t be returning to my blog and casually reading content again. If so, they can always re-subscribe if they wish. (And I’m not planning on hiding much, if any, content behind a free wall in any case).