Hotels often provide complimentary upgrades when they have better rooms which are unsold. The idea is that they want to spoil you with the better room to increase the odds you'll pay for it next time. Some operations--particularly cruise lines--will intentionally overbook lower priced rooms / cabins, and the upgrade as many customers as is necessary.
DVC policy is no free upgrades. All owners are to be treated as equally as possible--if one owner gets a Savanna View AKV Studio for 20 points per night, every other owner should pay the same 20 points for the same room.
And, as another poster pointed out, DVC and other timeshares usually operate very close to 100% occupancy.
The only time upgrades occur is due to some computer glitch or unexpected maintenance issue at the resort. If they have 20 reservations for Standard View Studios and only 19 rooms available due to some unanticipated issue, someone will probably be upgraded. (Even then they try to pick someone with a very short stay so that the upgrade is minimized. They'd much rather upgrade someone with a 2-night reservation rather than someone who is booked for a week or more.)
Note that at AKV there are some rooms classified as Standard View which do have a partial Savanna View. That's not an upgrade--the rooms were specifically classified Standard so that someone paying Savanna View points didn't get a crappy partial Savanna view.
Been a member 10 years and have taken 25-30 trips. Closest thing we've had to a "free upgrade" is when we were forced to switch resorts due to issues with our assigned villa. Nothing else was available at that resort. When they moved us, we did end up in a room which cost more points per night than what we had booked. But all things considered, I would have much rather been able to stay where we booked and not had to spend 3-4 hours packing and unpacking unexpectedly.
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