According to a recent change proposal, the development team is considering this change for Fedora 37, which will be released later this year, in order to move forward with deprecating legacy BIOS and making UEFI a hard requirement for x86_64 systems. While the change may not be overnight, new Fedora x86_64 installations will not work on non-UEFI platforms.
In a gradual manner, Fedora plans to completely remove support for legacy BIOS. However, users of older systems can still upgrade to Fedora 37 via an update (instead of a fresh install).
At the same time, Fedora is also phasing out the 32-bit x86 operating system and changing the minimum system requirements to circa 2006 hardware. So aside from a small group of users who have UEFI support disabled on their hardware, this new change shouldn’t affect too many people.
It is reported that Unified Extensible Host Interface (UEFI) is already a requirement for secure boot via FWUPD, or system capsule firmware update. After the proposal period, it is expected to be approved by FESCo, and support for legacy BIOS will be completely removed in a release shortly after Fedora 37.