Apple will not release the ``USB Type-C compatible charging case'' for the 2nd generation AirPods Pro separately, and you will need to repurchase the entire device to switch to USB Type-C.

At Apple's new product announcement event held on September 13, 2023, Japan time, it was announced that the iPhone 15 series finally abolished Apple's proprietary Lightning standard and transitioned to USB Type-C . At the same time, Apple announced that the 2nd generation AirPods Pro will also be upgraded to USB Type-C charging, but the AirPods Pro charging case that supports USB Type-C will not be sold separately and will be replaced with USB Type-C. It turns out that in order to upgrade, I have to replace the AirPods Pro entirely.

Apple Not Offering USB-C AirPods Pro Cases As a Standalone Purchase - MacRumors
https://www.macrumors.com/2023/09/13/usb-c-airpods-pro-case-not-sold-separately/

Want USB-C AirPods Pro? You'll have to pay full price | iMore
https://www.imore.com/airpods/want-usb-c-airpods-pro-youll-have-to-pay-full-price

The iPhone 15 series finally uses USB Type-C, making it possible to charge the iPhone with the same cable as the iPad and MacBook. Apple has already started selling ``USB Type-C charging cable compatible with high-speed charging'' and ``USB Type-C to Lightning conversion adapter'' at its official store.

Apple starts selling ``USB-C charging cable compatible with high-speed charging'' and ``USB-C to Lightning conversion adapter'' - GIGAZINE

At the same time, Apple also upgraded the second generation AirPods Pro to USB Type-C. Apple says, ``Easily charge your Mac, iPad, AirPods, and iPhone 15 lineup with a single cable.'' At the time of article creation, reservation acceptance for the 2nd generation AirPods Pro compatible with USB Type-C has already started, and the sales start date is September 22nd, the same as the iPhone 15 series.

Apple upgrades AirPods Pro (2nd generation) to USB-C charging - Apple (Japan)
https://www.apple.com/jp/newsroom/2023/09/apple-upgrades-airpods-pro-2nd-generation-with-usb-c-charging/

However, Apple does not sell the USB Type-C compatible charging case for the 2nd generation AirPods Pro separately. In other words, users who want to switch their 2nd generation AirPods Pro to support USB Type-C will have to replace the AirPods Pro entirely.

Regarding this policy, technology media MacRumors points out that the reason for this may be that the 2nd generation AirPods Pro, which supports USB Type-C, not only changes the charging standard but also improves other functions. The new 2nd generation AirPods Pro not only upgrades the main body and case to IP54 dust and water resistance, but also enables ultra-low latency and lossless audio when combined with Apple Vision Pro . It seems like they want you to replace the AirPods Pro entirely.

However, by not giving you the option to purchase a USB Type-C compatible charging case, you are forced to carry around a 'USB Type-C cable for charging iPhone and other devices' and a 'Lightning cable for charging AirPods Pro'. MacRumors and others have pointed out that this could frustrate users who don't get much benefit.

The 2nd generation AirPods Pro, which supports USB Type-C, is available for pre-order at the official store for 39,800 yen including tax.

Purchase AirPods Pro (2nd generation) - Apple (Japan)
https://www.apple.com/jp/shop/product/MTJV3J/A/airpods-pro