FWIW, I've stayed here almost ten times over the years, as both a Diamond member (at the time) and as a Globalist Guest of Honor, always on points, and have not been upgraded to a Suite just one of those times. The rest have been in either Studio Suites or the 1-bedroom suites (non-city view level). It's a mix of getting lucky, occasionally asking in advance, and asking at check-in if not proactively offered.