There are $uites at Poly, but no Grand Villas.
The reality is that it is very rare to get a Grand Villa as a cash booking. All Grand Villas (not suites, but the villas) are DVC units, owned within the timeshare association. While Disney themselves own points and can take units with their points, and them place them within the cash booking system, Disney are subject to the same rules of booking as other owners -- 11 months with points they own at a resort, 7 at any. And the units they pull for longer range booking tend to the smaller sizes. GVs on cash are outrageously expensive, and because Disney have to kind of "lock in" date ranges for availability, counting on the Disney-blocked dates and a consumer's demand for the unit for cash coinciding just doesn't work out well.