A Detective Pikachu blister pack will soon be available at 7-11 stores in the United States. Each comes with one Detective Pikachu booster pack, a regular booster pack, and a plastic Pokemon coin.
I called a couple 7-11 stores in Los Angeles but none of them have it yet or knows how much it will cost (although they do have Detective Pikachu-themed cups). They will probably start getting them over the next few weeks.
Like the Detective Pikachu Walmart tins, this product was not announced before because it is exclusive to 7-11 stores. Thus, distributors did not post information about it since Pokemon is dealing directly with 7-11.