If the company is forcing you to put reminders instead of just letting you cancel right away, that's a dark pattern. I do not know about Linkedin, but I've seen plenty doing this, like Amazon.

I assume they all let you cancel.

If the subscription is free, and they do not let you keep the benefits if you cancel, then I would still not describe that as a dark pattern.

Amazon does not let you cancel and keep it for the month. As soon as you cancel it, your subscription ends.

I agree that is a dark pattern.

You're probably right... I suppose at the very least I could label them as "predatory". But yeah, still more a personal problem there, duly noted.

Ease of entry and exit should be roughly equivalent. Another perspective that makes it clearer; any attempt to trick or subvert the will of another is a dark pattern.

Transparency here is a distraction, plenty of tricks still work great even when people can see them coming. Focus on the intent and the result however and it becomes clear.

It would make more sense to ask the user if they wish to transition from the trial into a subscription. If they don't, consider giving them an exit survey.