The Anniversary Edition content includes the 1m credit microtransaction along with 4 DLC car packs and a content pack of paint, gear, avatars and themes. It's a sort of all-in-one code for multiple discreet packs.
The Precision Pack is just 5 cars.
TBH, I think people are not necessarily clear on the pre-orders
AND from where. For example, here is the release information for the
EU PSN Anniversary Edition:
"With the Special Edition, you’ll get the full GT6 Game, 20 extra cars (Torque, Performance, Adrenaline and Velocity packs), custom PSN avatars, paint chips, race suits and race helmets – basically everything you need to fly past your friends on the way to the finish line. And, pre-ordering either of the editions on the store before launch will get you the great cars included in the Precision Pack for free."
No mention of 1 Million credits.
I can also find no mention of the credit pack for the Standard Game Edition from the PSN store, only that the Precision DLC will be included.
HOWEVER, retailers like Amazon UK, did offer a 1 Million incentive.
I do not know why the industry has made these incentives so splintered and confusing.