Yes, this is quite noticeable at higher end "aspirational" properties like PHP and PHK, and also at "good value redemptions" like GH Taipei (Cat 3), GH Macau (Cat 4) and PH Saigon (Cat 5). I don't know to what extent this is attributable to properties (or Hyatt) playing games. It's certainly possible that people are trying to salvage their points and there has been a massive spike in bookings. Although IMO for some of these hotels the lack of availability occured rather abruptly, immediately after the announcement.