I'll never rip on Yota's pickups, BUT, this frame issue begs for some questions to be answered.
Agreed answered questions yes but that does not mean that they should be taking them all off the road.
And not necessarily for the purpose of splitting hairs. My understanding of the problem after several hours of searching is not the frame it is the undercoating that was faulty. Which before you say it is what protects the frame, that itself is very fixable if found early on. That is the reason for the inspection, then they can be repaired before a problem exists. I think this is actually a good way to handle the problem, at least as good as any other car manufacturer has handled their found faults. example is Ford's Pinto rear end collision issue used in the original posters link.
Again though finding out how this happened and making sure it does not happen again should be priority one and they already have the other priority taken care of which is locating the problem trucks and making amends. The rest of the location part though is going to be at the discretion of the owners to bring them in for inspections.
As a final note here, I will admit that mine has not been inspected by Toyota for bad undercoating or excessive frame rust. The reason is simple, in this state yearly inspections are required and part of that is a frame inspection looking for excessive rust and or rust holes. I know that is part of it because that old Gremlin that I had failed for that very thing amoungst other problems. That was the day the Gremlin finally died (hangs head in sorrow).