Computerization probably renders many of these issues insignifcant
We talk here about depositing weeks and Trust points almost as if things were like they were 30 years ago. It is almost as if Marriott has to pick up a piece of paper and move it somewhere in order to deposit a week into the exchange inventory. I was a programmer for many years in a past life. I was also an Oracle database administrator for a number of years. All of these Marriott programs - the Trust, the Exchange company, the resorts - are all either owned or managed by Marriott. That makes it pretty easy to create a central inventory database containing all of the weeks managed by Marriott. You would not need three databases - one for the weeks inventory, one for the points inventory, and one for the Trust inventory. You can do it easiest with just one database. One way would be to have a category field for each week (or whatever division they choose) that designates what category the week belongs to (e.g., W for weeks, T for Trust, E for Exchange, and other codes for other categories). Then you can move a week around by just changing the letter designator. That can happen instantaneously. You could also have a availability flag. Set the flag to a 1 if the week is available to be searched by the points exchange search engine, and set it to 0 if it is not searchable. Then to drop weeks into the Exchange inventory (i.e., deposit them), you just set the availability flag to a 1 for each week to be made searchable. Presto! You can instantly deposit scores of weeks into the exchange inventory without physically moving anything or doing any paperwork. I don't know if they actually did it this way, but I could have created a database for them; and there was a time I could have written a lot of the software.
Since Marriott controls or manages all of these facilities, it becomes somewhat of a mute point as to whether they can move inventory around or have inventory searchable or not seachable. They control everything. So, they can pretty do whatever they want whenever they want. Fortunately, they have every incentive to make the Points program a major success, and I suspect they will do whatever it takes to make that happen. They are not going to allow unused weeks to just lay around if someone actually wants them. That would make no sense.