If a payment connector is configured and sales orders are created with credit cards authorized and for some reason the payment service is removed from the online store, accounts receivables payment processing or the hardware profile, the sales order will not be able to be processed because you will receive an error message:

“A merchant account for Service account ID %1 was not found. Reestablish merchant account information for the payment service account.”

Due to the complexity of the behavior change and risk of regressions, this would be a feature request and I have created this Product Suggestion.