OK, I am curious ? Just what exactly is this "defunct model" of HD PVR that you have been renting for 8 years ? I am struggling to recall any "defunct model" that would have been working recently that has NOT been swapped out by Bell TV for a newer model, especially under a Rental Scheme. The 9200 is AFAIK
the ONLY HD PVR that has ever gone "defunct" in the history of Bell TV and that model was swapped out, free of charge by Bell for a 9242 or a 9241 & 5900, to ALL customers, Rental Or ORS (Out Right Sale).
To answer your question, all they require is the Receiver and Remotes. If you look at the address label, it will not be going to Bell anyway, or I doubt it very much, it normally goes to a company that will refurbish and repair receivers. When the package arrives at the detination, the Serial Number is scanned, removed from the "Active Receiver Database" and also therefore your account and that is it. 99% of the time, the remotes are thrown straight in the garbage, as Bell have no way to repair/re-sell used remotes.
OK, I see that earlier in the year you were asking about and were troubleshooting a 9242, that is NOT a "defunct model" if this is what you are referring to as such, because, believe it or not, there is still a stock, albeit a small stock, of the 9242's as refurbished receivers and so it might be that if the receiver you are sending back is a 9242, it could be refurbished and put into that stock pile.