As other said it's usually not a problem to ask again for the credit card, and when you switch payment services the users might actually see different details i

As other said it's usually not a problem to ask again for the credit card, and when you switch payment services the users might actually see different details in their bank transactions, get billed with different delays or otherwise have billing problems. Having a transition step where the users know something is changing can be helpful to cover the edge cases.