Or they interpret any kind of interaction after a while of inactivity as "yes please sign me up for all your newsletters, even though I previously explicitly told you to unsubscribe me"
Throw something in the cart at a random website? Now you're on their mailing list and get reminders to finish checking out. Doesn't matter that you never consented. I don't know how this isn't a violate of the CAN-SPAM act
What happens- at scale and I have to believe deliberately- is the “checkout created” event with that flag set to true is considered as “opted-in” by the marketing automation platforms everyone uses, like Klayvio.
Even if you immediately un-check it, un-checking doesn’t trigger an unsubscribe event, since you never submitted the form in the first place.
And because your Shopify session is now shared across stores, your email address gets opted-into marketing just visiting a checkout page.
And of course, follow-up mails for abandoned carts are an optional setting too.
My theory is it started by accident- if you get a notification that says, “this checkout, this email, agrees to marketing: true”, it sure reads like an opt-in, and it used to be reliable. But it’s not anymore, because your email is already attached to the checkout when its created.
“Agrees to Marketing” pre-dates the global Shop session by years, it’s plausibly an ecosystem bug; one with no real motivation to solve until customers start talking (more)