I don't know all of the ins and outs of shutting down GT5, but people lost a lot of stuff (assets).
Apparently, GT6 is not designed in the same way, so when they shut it down, that same thing should not happen. At least that was how it was explained to me about licences, although I am not sure what else has been taken off of the GT6 servers yet and added to our game save. Fingers crossed...