I hope this is not true, because if it is, it actually creates some of the headaches and disappointment that folks report when they don't receive their request.
For example: Family A requests adjoining and means nearby, no need for an interior connecting door, they actually don't want that closeness. But the room assignors automatically assume FamilyA meant connecting and assign connecting rooms. FamilyB requests connecting and really wants that interior door so grandma can more easily babysit. However, because FamilyA was given the last pair of connecting rooms (that they don't need) FamilyB is stuck with rooms 3 doors away from each other. Seems wasteful and creates 2 families disappointed with their accommodations. Following the requests as made would have resulted in 2 happy families.