Bo here from Shopify Support
That is a great question. Any stores that are sold through the Exchange Marketplace will have your credit card details removed automatically once the ownership has been transferred to the new owner. I would definitely recommend taking a look at our guide on how the exchange process works here. We also have a blog "Am I Ready to Sell My Ecommerce Business? Here's How to Find Out" that is super informative and well worth the read.
Best of luck with selling your store!
All the Best,