I was wondering too why anyone would ever want this…but the proposal explains it:

Support for UEFI on MBR was originally added in blivet#764 to accommodate cloud image use cases, such as AWS, which at the time did not support UEFI booting on GPT disks. These constraints no longer apply to modern cloud platforms, making MBR-based UEFI setups unnecessary for current Fedora deployments.

So basically it was some workaround a few years ago. I have a hard time to see any reason speaking against the removal.