Susan- that's true, but I would think that any executive would be very careful in putting anything which might later be misconstrued in writing if that wasn't, in fact, the case. And contrary to the rumors bandied about, I do believe the upper echelons have at least the outline and major logistics of whatever plan they intend to enact already in place. And yes, if the plans did subsequently change any latter statement would supersede the first,as you pointed out, and could not be represented as being fallacious as long as at the time it was written it was the intended policy. I just really don't think any written official policy would have been offered if, in fact, there wasn't already a predetermined policy.
Although you maintain that every week is assumed to be of equal value unless specifically stated otherwise, as pointed out by someone else earlier, by virtue of the fact that Marriott itself assigns different values by charging different rates to the public interested in renting different weeks, it would be easy to make a compelling legal argument that the weeks do, in fact, vary in value.
I guess the bottom line remains whether Marriott has a contractual obligation to continue to allow each owner to have the potential to book each week in their owned season or if they can, at will, decide to change the reservation system in any fashion that they deem fit, including assigning even a single week in the purchased season to any given owner. Although you are certain that "if every owner has available to him/her a week as purchased, subject to eligibility requirements, the contractual burden of MVCI to provide a week is met," if, in fact, Marriott has the obligation to allow each owner the potential to book each week, then simply ensuring that every owner has available a week does not fulfill their contractual obligation.
Furthermore, even if the contract is read such that there is some ambiguity, Marriott has always sold their units with the promise of owners being able to potentially book any week in their season. The way they carefully designed the 13/12 month reservation rule I think underscores that Marriott recognizes this obligation. The reservation would be much simpler for them and less costly to administrate if they simply said that multiple week owners could book at 13 months and single week owners at 12 months, without reserving half the inventory of EACH week until every owner had the potential to book. I think it was crafted this way for a reason.
And I certainly hope this is the case, because if it is not, then not only would resale weeks be potentially affected, but an awful precedent would be set that, in my opinion, should give anyone pause about ever buying a Marirott timeshare. I would hate to think that I could happily purchase a unit and that somewhere down the road, at Marriott's discretion, they could suddenly decide to allow multiple week owners to have first crack at all the weeks. If, as you suggest, Marriott doesn't have to ensure that every owner has the potential to book each week in their owned season, then it puts all owners (not just resale owners) in jeopardy. To me, that's a scary concept.