Not sure if this is more like the next NSX after Gen 2 the (2015) model or if they are mistaken and it's more like another Honda sportscar (S2000 equivalent) that will also be branded as a McLaren as well. Kind of like the BRZ/FRS setup between Subaru and Toyota
We know Mclaren already has a high end supercar "P1"then the low end supercar "12C" (which I'm assuming the NSX is it's rival here) and so now it would make sense for a low level entry sports car (FR convertable next S2000) for both.
I could be wrong and I'm pretty certain some more news will come to light to clarify it since it's been leaked out already.