I don't live in the US, and so I am not certain exactly how the TSA operate. I believe they are not connected to the airlines, and that they handle security at the airports independently (as well as other things).
In the UK, the security operation is completely independent from the airlines.
The recall for these MBPs is quite specific, and the TSA/FAA rules are for the safety of the general public.
If I were responsible for airport security, I would proceed on this basis:
I already have laptops out of bags, so it should be very simple to identify an apple machine. I separate these machines at security, not at the gate. I check the serial number, and enter it into the apple website at security. The apple website tells me if the machine is affected or not, including if the machine has had the necessary replacement (which I don't care about as long as it's now considered "safe").
This process shouldn't take more than a couple of minutes. It's no more intrusive than the random checks that are imposed upon individuals for all sorts of reasons at this stage in the process of security checks at airports in my experience. And yes, I have flown a great deal around the world, and usually carry various electronic devices.
I understand that TSA and other security staff are unlikely to be very good at distinguishing which model of machine you might have with you, but that's what the web site is for. The biggest risk here is fat-fingering the serial number into the web site.
Maybe, as an additional comfort for the airline, they pop your laptop into a sealed clear plastic bag, shown as checked, and you can't use it until you board the aircraft... a pain in the backside, but better than being on a flight with an exploding laptop.
The crunch comes when you turn up with a machine which is affected, and they say you can't fly with it. Bear in mind the FAA ruling here states you're not allowed it in the luggage hold either... so switched on or switched off... there's going to be very little you can do at this stage other than allow them to destroy it, or take it home and miss your flight.