I haven't flashed it yet... I'll probably get around to doing it this weekend. Several people in the thread said they were able to backup and restore now. I did notice that there has been a revision since he posted it though. The Sprint version is listed as working with no issues. 
[RECOVERY] TWRP2.6.3.7 TeamWin Recovery Project 10/23 - xda-developers
TeamWin Projects - TWRP 2.6 - Samsung Galaxy Note 3 (Sprint) | TeamWin

[RECOVERY] TWRP2.6.3.7 TeamWin Recovery Project 10/23 - xda-developers
TeamWin Projects - TWRP 2.6 - Samsung Galaxy Note 3 (Sprint) | TeamWin
As far as I have read of it, it appears to be in N3's everywhere and the idea seems to be that it is something Samsung is going to have to address that is related to Knox.
. But then i read that unrooted devices are getting the same message. Either way it's still a kick a$$ phone, just in the early stages of root glory