Zipatile from Zipato has been out for about a year and has both Z wave and zigbee antennas. It can be made to interface with SmartThings through MQTT. Or you can try adding it as a secondary Z wave controller. It costs about twice as much as the Indiegogo price for lynky but, you know, it’s real. 
It’s basically an android tablet with the IOT radios added.
There’s a discussion thread in the community about it, but I don’t know too many people who would have this and SmartThings, but you never know.
And of course the newly announced ADT/SmartThings security panel
will be a touchscreen device that has both Z wave and zigbee radios in it, although we have yet to see any screenshots of the SmartThings UI.
https://www.smartthings.com/adt#/
So obviously it is possible to put a Z wave and a zigbee radio in a tablet.
If the lynky ever does go into full production, obviously a big if, my guess is that they are intending to position it against Amazon’s echo plus offering. The problem with that is by the time the Lynky is actually available, Amazon will probably have a competing video tablet option that costs even less.