It's official, this answers our question.
(officially) We do not have to clip coupons anymore. You can just show your coupon books without clipping them. Additionally, you don't have to have coupon book with you. If you have a smart phone, you can show coupons from your mobile app. Your cashier will honor the coupon you show on your mobile app.
* At this point, I will not be surprised if a lot of Costco warehouses apply coupon discounts to every shoppers automatically, without asking for coupons.
Until this point, officially, we were supposed to clip coupons. That's why they say ""No more clipping coupons"