I have received that once for a stay at Rydges in Sydney and once for a stay at Rydges in Melbourne. In emails that referred to a particular bookings. But looking at the terms and conditions it looks like the offer is available for any booking, as long as upgrade rooms are available. But I have never used it.
At least for the Rydges Melbourne hotel it isn't really much of an upgrade as many of the smaller rooms are nicer than the bigger suites.