The RHEL installer includes an EFI System Partition of between 200MB and 600MB by default, of which the lower size is much too small for firmware updates on modern hardware and also for future bootloader features like UKI. This change will increase the minimum size of the ESP to be 500MB, which is also the same value used by Microsoft for Windows 10 and newer.

Detailed description for Fedora 39 can be found here:
https://fedoraproject.org/wiki/Changes/EnableFwupdRefreshByDefault