The Fedora Workstation Working Group has decided that Wayland simply isn't ready yet to replace an X.Org/X11 Server by default, although much progress was made on getting Wayland to feature parity with the X.Org-based stack, they didn't cross the finish line. Fedora defaulting to Wayland will now be deferred to Fedora 25 later in the year.
Hopefully by the time GNOME 3.22 rolls around and other improvements made to related projects, Wayland will be more primed for making its debut as powering the default Fedora desktop... Fedora 25 will be released right around the time of Ubuntu 16.10, which is meanwhile hoping to make Mir and Unity 8 the default on their desktop, assuming they don't run into any further obstacles.
The current state of Wayland functionality on Fedora can be found via this Wiki page.
While Wayland Fedora 24 didn't make it as the default, from the GNOME log-in screen you can still opt to use a Wayland-based session if you so desire. Developer Matthias Clasen wrote a blog post today with a few more thoughts on why Wayland is ultimately the superior solution to X.