Let's see what other countries do
I suppose the test will be what the UK and France do, as they have access to substantially the same facts.
Banning large batteries from the cabin isn't the worst idea. It's basically a decision that they'd like to deal with explosions of 150g to 1000g of explosive in the hold rather than in the cabin. The list of airports seems approximately where a substitution of battery for explosive could be expected which also have flights to the USA.
I also wonder if the agencies are concerned about an explosive laptop being used as a tool in a larger scheme, such as breaching the flight deck door.