Apple - What is the effect of the choice to "set up as new iPad"?
CONFIRMED BY MYSELF on my new iPad mini 4 and iTunes 12.
If you select "Set up as new iPad" and hit Enter you'll get a new window with "Sync with iTunes" message and a blue button with white letters Get Started. After hitting this button you'll get a iTunes window for your attached device with all the relevant information, Backups and other Options.
In other words, if you select "Set up as new iPad" * NOTHING IS CHANGED IN THE ATTACHED DEVICE * it is only attached to iTunes for subsequent actions.
You can rename your iPad on the device itself: go to "Settings"->"General"->"About"->"Name".
If you have never connected or synced this iPad to this computer via iTunes, it keeps ask you to set it up as new, or restore it. Choose "Set up as a new iPad"; don't worry iTunes won't wipe your iPad, it will just tell iTunes this is a new device and now you can sync this device or make a backup if you like.