Ubuntu Touch is currently in a weird state with regard to Nexus 7 support in that the current pre-release build doesn't support the newer, far superior Nexus 7 2013 model (razor), only the older model (grouper), but Canonical also has announced that moving forward grouper support will be killed and only razor will be supported.

Considering it is all in a developer preview state at this point, this isn't a big deal but may be important information for anyone thinking about buying a nexus 7 right now to be used as a native Ubuntu device.