I had a feeling it would end up being a store by store decision as to whether a particular cashier or manager would honor it for the Entertainment Cards or not. As a lawyer, I encourage everyone to be persistent and firm in asking the manager to honor it their store today if they want to use the coupon for entertainment cards.
It absolutely could be considered a deceptive practice for Target to honor promotional discounts (Red Card and Pharm Rewards) on those cards for all other promotions and then try to exclude them today without specifically noting it on the coupon or in any of the ads they ran. Assert your rights as a consumer, and try to force them to honor it!! (I'm not encouraging anyone to get nasty with the employees, just be persistent and firm.)