Currently there are two primary use cases for syslinux on RHEL:

1) Install media: syslinux is the bootloader used for install media.

2) PXE: syslinux is used for PXE booting on legacy BIOS x86_64 systems.

But syslinux is in practice not maintained in upstream and the bootloader team doesn't have the same level of expertise with syslinux that has with other bootloaders such as GRUB.

Instead of having to maintain different bootloaders for x86, it may be better to replace syslinux for GRUB in RHEL10. For the two mentioned use cases, the following could be done:

1) Use GRUB in install media as a bootloader instead of syslinux.

2) Use GRUB as a PXE payload. This may be tricky for legacy BIOS but it should work properly for EFI environments. Legacy BIOS support is expected to be dropped for RHEL10, so this shouldn't be a problem.