Will unassigning my Wix site from a premium plan cancel that plan?
No, unassigning a site from a premium plan will not cancel that plan. The plan can be reassigned to a different site.
To cancel a premium plan: Sign in to your Wix account > hover over Subscriptions > click Premium Plans.
Next to the relevant plan, click Manage > next to Next Payment, click Cancel payments.
Canceling your Wix premium plan will not cancel any domain, app or mailbox subscriptions that you have with Wix. You can cancel your domain, app, or mailbox subscription via the Billing & Payment tab, under Manage Premium.