There's several reasons to think this is the case: Players have reported seeing card results appear in the Wonder Pick before the carousel choice is made , implying that the rewards are fixed from the moment you choose (thanks to @PokeNinaa) Choosing to mass-open 10 card packs at once doesn't let you pick the packs from the carousel, implying the choice is irrelevant and a bent corner doesn't matter
Careful selection transforms your deck's competitive potential
Now, according to @AskTarget, Target's official support account on Twitter, they have plans to reverse this decision, presumably as a litmus test to see if scalpers will continue to act inappropriately
Graded Population Report: Here Comes Team Rocket #111 Visualize the distrbution of grades in the chart
The best decks are built around optimizing just a few incredibly powerful Pokemon, so make sure to utilize the vast array of Trainers to make your deck as consistent and powerful as possible
Weighed packs, to me anyways, have become so prevalent because of the urge to open old WOTC product as of late