The RPi4 has had a functional port of TianoCore for a while now, which is likely what they were referring to. You can use e.g. generic aarch64 UEFI Fedora images out of the box with it.
RasPi 4 requires some special files in the EFI system partition and a special non-stock EEPROM, at least for the older RasPi 4 boards, maybe the newer stock come with the UEFI-enabled EEPROM image? Regardless, in my experience with other EFI-enabled boards, I've never had to put the actual EFI into the EFI system partition, the EFI itself lives in a SPI flash usually so that you can boot "from" EFI with no "disks" attached.
Definitely the RasPi 4 having the ability to run UEFI, even in this way, is good. But what I'm looking for specifically is having UEFI just like every other UEFI-enabled PC and server does it, where I don't need a disk to boot to UEFI.
https://github.com/pftf/RPi4