Changes are coming, but details are kind of scarce.
Logo for Final Fantasy 14. It has the title over a black background.

On the Final Fantasy XIV (14) hub site, Lodestone, an announcement was made saying that there are changes coming soon for purchases and subscriptions. Square Enix says that they are planning to change their payment processor in late February. This will impact subscriptions and purchases made through the Final Fantasy 14 Mog Station, Online Store, and Square Enix Account Management sites.

Square Enix says that they don't expect this to have an impact on most purchases, but they wanted to get out ahead of this to communicate any potential changes.

The change should not impact customers who are currently enrolled in a recurring subscription plan. However, future updates to an existing recurring subscription, such as starting a new recurring subscription or making updates to the payment method on existing recurring subscriptions, will be processed through the new payment processor. Switching an existing recurring subscription plan to the new payment processor will require the re-registration of their payment method. Although the current payment processor will continue to be available for a period following the change, we recommend updating an active recurring subscription after the change occurs as this will help prevent any account access disruptions in the event that the current payment processor is no longer available.
They go on to say that there will be some existing payment methods that will no longer be available after the change. They hope to reintroduce these removed payment methods over time if possible. The payment methods being removed include: JCB, Carte Bleue, and SEPA (Sofort). The payment methods that will be available include: Visa, Mastercard, American Express, Discover, PayPal, Amazon Pay, and Paysafecard.

Additionally, customers may notice other minor differences following the change: the manner in which credit card charges show up on billing statements may be slightly different, or banks may request fraud verification on purchases that used to be approved without such additional steps. While the changes should not impact purchases, we do recommend our customers to review any charges made after the change for due diligence purposes, and to ensure any charges are for purchases made from Square Enix.