if it's acting like the spoofer (replacing version.bin string) then it will not be effective, as we could update without issues the remaining titles. each title has a version, and can be updated independently. that was the same on the Wii.
If he only patched the "system menu" title's version, other system files and titles could be updated?
I don't know enough the WiiU file structure, but seeing wiiubrew and all the system title database, there are a lot of different things which would require to be spoofed to prevent an update on different titles. and still, they could release a new title not present in the console, therefore not patched yet.
Unless he patched the function used to check and return each title's version, instead of patching the actual title version. in that case, it should be safe as long as no game/app rely on that returned value for anything else than update.
