No, unsubscribing does not require a confirmation email. Subscribers will use the unsubscribe link in their emails. Or they can use a profile page or unsubscribe module on your website when they are logged in to your website.
To prevent strangers from randomly unsubscribing users you can add a security to prevent this. When you visit the Subscription tab in Acymailing->Configuration you can select what unidentified users can change. Set the option to NO and you're good to go.
Both logged in users and users clicking on the unsubscribe link in their email are identified users. The unsubscribe link in the emails contain user information to identify them.
It's documented here: https://docs.acymailing.com/setup/configuration/subscription
