SGS offers suite upgrades to all eligible levels (Platinum and up) when they are available. The point being made in this thread is that there are fewer non-occupied suites these days for them to use for complimentary upgrades.

Being an Ambassador helps but then this hotel gets a lot of return elite guests who might be prioritised over a first time Ambassador. It is difficult to say whether or not you would get a suite upgrade, but I would suggest your odds are not super high just because 3rd January will be a busy time with a lot of those guests staying over NYE probably still around. Then again you might get lucky. If you really want a suite, you should book one or find another hotel that almost guarantees an upgrade to elites.