In no uncertain terms it states the discount only applies to items listed as a Preorder. None of those games show a Prime discount for me and this was a huge deal for other people as well.
I mean, you can call it whatever you want, but...
Wolfenstein II: The New Colossus on PlayStation 4
I made sure to include the date & time so you can see for yourself that they're up to date.
If you consider that something different than "the Prime discount", you can, but it's clearly $7 cheaper on Amazon.
Assassin's Creed Origins on PlayStation 4
Assassin's Creed Origins on Xbox One
Again, date/time are included, and, again, Amazon is cheaper, regardless of what label you give the discount.
As for Super Mario Odyssey, Amazon doesn't have it in stock (the $59.99 price is from a third party seller doing FBA).