ok, i will share my experience... I bought a N9 since the first week it was release and it came with the "poor" finish, a bit more shiny but prone to chipping...after some time I bought a few other N9s, both on 16 gb and 64 GB in black and cyan...and also bought cases from ebay..all these with matte finish

so I concluded that the N9 came originaly with the poor finish which was leading to chipping and later it was eventually switched to the matte black the Lumias have. The lumias never had the poor black. So dont worry, the matte black and the poor finish are both original casing, just the poor black was switched later in production to prevent chipping.