There are a whole horde of WoBs out in Theoryland. Over the years, diligent Sharders have wheedled bits of information out of him question by question.
Mistborn can burn all of the Allomantic metals, so if there were a new Mistborn pop up, they should be able to burn the normal 16 (this includes Cadmium and Bendalloy, as Preservation had swapped them out during the FE era for various reasons), as well as the godmetals and their alloys.