I was told: "To book using points to upgrade, the hotel will need to have suites alloted as available to book for points. Suites are not held to the same rules as standard rooms. If a standard room, as defined by the hotel, is available for a standard rate it must also be available for Free Night Awards and full points. For suites, hotels get to decide how many can be booked using points, whether as full points or an upgrade. I would be happy to check the availability of what you are thinking of booking. Which hotel and what dates did you have in mind?" and "Currently for those dates I show that they are only accepting full points for suites. We do not have the 9,000 points option available. Do you have any flexibility to your dates? I'm happy to check extended availability."

I think I used poor terminology - the two (what I'm calling) buckets may rely on the same underlying 'inventory,' but the two buckets do not always have identical 'availability' - that was all I was trying to convey.