While the 4.6 GNOME live environment boots into X11, with 4.7 it will boot into Wayland by default.
I looked to see if there's a way to get to a Wayland session in the current live environment, but I didn't find anything that worked.
We plan on working on Release Candidate ISOs in the near future to get ready for the 4.7 release. If you'd like to help us test those, you can get access by joining the Release Testers on our OpenCollective.