It's 100% correct, and it is stated on the BBS module page. I also have verify this in use: I had a Td5 only unlock when I first got the EVO in early 2011. I was still able to access SLABS, ACE, BCU and Autobox on a fellow AULROians V8 D2 despite not having the V8 unlock.
In regards to the supposed problem with the Nanocom resetting radio codes, the only way you can do that is by cutting permanent power to the Radio : the diagnostic socket and permanent battery supply to the radio memory (which holds the radio code) share the same fuse. I'm guessing someone was a tad careless plugging into the diagnostic socket and blew the fuse :angel:

