They could as newer releases have spec 2.0 on the disc, but does your theory make you eager to play GT6?
We need to know why PD decided to release a new game instead of GT5 Spec 3.0 and more DLC packs.
So far I can't find a reason aside from the possibility that the studio needs a financial boost before going serious with the PS4. Yes, for GT fans it's probably a no brainer to buy it, but the game also has to make sure that we remain loyal. Here's hoping TGS will be a GT6 revelation.