It is quite clear now that since the big reveal on 2 Nov 2017, Singapore Airlines has restricted the new Suites Saver award space on SQ221 and SQ232 from Singapore to Sydney and back, starting from 18 Dec 2017. In fact, a quick search online shows no Saver award space for Suites on these flights.
Singapore Airlines, however, has still kept Saver award space open for the previous generation Suites, on all existing sectors operated by A380 aircraft. In fact, you can still waitlist yourself on the only other flight operated by an A380 from Singapore to Sydney on SQ231 on 18 Dec 2017, the same day the new cabin products will debut on SQ221 to Sydney.
In my opinion, if you are not willing to splurge your miles just to try the new Suites, it might be worthwhile spending it on the previous generation Suites. It is, after all, a splendid product! Since everyone is flocking to try the new Suites, I don’t suggest that you should defer any plans just to try them out. Instead, take this opportunity to redeem a Saver award on the previous generation Suites.