For Canon lenses, that information is found in the patent for the lens (when it is possible to associate a released lens with its patent, and that is not always possible).
You have a point. Don't you reckon they refresh the 30mm f/1.4 first, since it released 2 years earlier than the 56 f/1.4? I have been eyeing that 56mm prime for a while as a cheap APS-C portrait lens with decent bokeh, but now I am unsure whether to get it or wait for a much improved MkII. My hope is that it releases before June...