If you browse to www.dlink.co.uk, go to "technical support" and select "DGS-1216T" from the list of models, you're presented with a page that asks you to choose your "HW revision" of the switch. There is a photo of the factory label (sticker on the switch chassis) with the HW version in a red circle. The HW version can be one of B1, C1 or Dx (the photo actually shows A1).
Based on your HW version, you're offered three different latest firmware versions that work only for a particular HW version.
Check your sticker to see which firmware version is appropriate for you. Download it and read the release notes - the features you're referring to are mentioned along with one of the updates. It may be interesting to read the release notes for the other versions too, to see the whole history of the model. I believe the features you're referring to were already present in / possible with C1 hardware.
If you mean to say that you're shopping for a new switch, it'll likely be the most recent HW revision, supposedly D<something>. Mine is one year old and it's already D1 hardware, with a chassis fan. Another specimen in our company is 4 months old and doesn't have a chassis fan anymore (silicon die-shrink on the inside?) - I don't know what HW revision that is :-)