Yes 16 node is really 20 node transistor density (both transistor pitch and metal pitch are same as 20) at higher wafer cost.
It makes no sense. Cost per transistor goes up (Moore's law goes backward)
Plus if that was not bad enough it is too costly to build and validate design IP for 2 nodes with the same transistor density.
This is why Altera, Cisco, Micro Semi and i hear likely another another left for intel. Intel''s 14 nm will have a real 14nm metal system and a real 14nm transistor density