The games are tied to the system at least thats the problem the way I understand on why you can't just transfer your games to another system. So yes using that logic if you did a factory reset you should be able to redownload the games again since they would be tied to that machine's mac address. Now if you system should stop working Nntendo should be to athorize the purchases made on that Wii U to another one if you still have access to that mac address or if send the system into them. Also with DDP it shows all your digital purchases so there is a record tied of the games tied to that NID . Now your saves will be lost but as long as you know what you look for and you have the time to give the people at Nintendo a headache you should be able to to redownload your games its just going to be a pain in the neck to do.
XBL Mii Verse-bigJnyc. Feel free to add me message me Gamefaqs. I get Nintendo systems for Mario and Zelda Xbox systems for Halo and Gears of War