First off this no-charge strategy is not confirmed.
Second what Samsung has been doing til now was installing nag screens and limiting battery charging to sixty percent. I'd be surprised if the US is the first country where they roll out no-charging. All their other methods were first launched in smaller markets.
Thirdly it is interesting they're supposedly software shutting-down the handsets and not simply denying them service. It'd be trivial to place every Note 7 on the blacklist maintained by US carriers for stolen devices.
Of course denying service means the devices are unreachable, so this might be the step before that, to ensure they're not kept around as wifi devices or fancy alarm clocks. Blocking the battery means they're effectively defanged - no charge means no chance of fire.
In my part of the world I haven't seen a Note 7 in weeks. I expect when a clerk points out a Note 7 is keeping a known fire hazard next to their genitals, or in their purse-of-important-stuff, or holding it to their face is asking for trouble, or charging it in their bedroom while sleeping is really scary, and insurance will no longer cover it's damages, the sane ones figure it's time to trade-in.