only thing ive noticed is, it doesnt wipe anything from your SD card, so your modules are still presant there, although they do not show up in the gui, you have to go through the install process again to relink them, as that is what i have had to do, i have checked the SD card and they have not been duplicated so it must just relink them
either that or it is just reinstalling them over the original lol, either way i dont care it works :)
EDIT AGAIN: Yep its definitely reinstalling them, i just spent 15 minutes doing rickroll again lol :)