The "Board SDK wizard" is functionality that we are trialing internally at present, rather than something intended for customer use at this stage. But basically its aim is to allow the generation of an "add-on" SDK package that provides information to the IDE on a customer / third party board by installing in combination with a standard SDK.
We'll be releasing more information/documentation on this functionality in due course. We strongly advise waiting until we do so before you investigate this functionality for yourself - as using it requires a very good level of understanding of how SDKs and the IDE interact.
MCUXpresso IDE Support
I too am interested in this. I can see that the New Board SDK Wizard is present in the current MCUXpresso. It was a year since the original question, is there an update on this?