Currently when setting up a RAID installation from Fedora's Anaconda installer it's using an LVM on top of MD RAID. But with the Fedora 26 release this summer they are looking at using LVM RAID directly.

Under this new change proposal whne using LVM partitioning and creating a RAID setup, LVM RAID would be used directly rather than creating an MD RAID device and using that as the physical volume for the LVM.

LVM RAID should offer the same functionality as MD RAID with it using much of the same code paths but the Red Hat developers believe it should offer better flexibility and be more future-proof down the road. This is just one of many recent feature / change proposals being talked about for the June release of Fedora 26.