I canceled a membership at the customer's request. A few hours later he changed his mind and I made the agreement active again. Since we had logged notes under the recurring events, they remained under the agreement however they did not return on the location page. They could not be attached to the visit. I had to add the recurring events manually. When the membership is re-activated, the recurring events should be available to too.
I typically "suspend" the membership first and give the customer a "grace" period, we log a follow up. If the customer doesn't call back, then I go back and cancel the membership and dismiss the available visit(s), so I can account for the deferred revenue.
If cancelled the membership and deleted the recurring service , but added a note before, visit will "remain" there for historical purpose but no actual visit is left. You can manually re-activate the membership and add the recurring service.
If you actually deleted the whole membership. You will need to "sell" a new memberships, as best practice recommended by ST and set the price as $0