The Hyatt Zilara Cancun Fans page on facebook seems to have a plethora of info on what's currently going on. You do have to request and be accepted into the group to be able to see most of the info.

I thought I'd read that the aforementioned lack of availability seemed to be more/only an issue for those booking under the timeshare side of the property(playa resorts?). Folks in the group say the property is definitely not closing for the upcoming renovations.