Back in '98 or '99, I had both my PS pump and AT replaced by the dealer under warranty. They did install inline filters on both. But, at that time, no-one could give me PN or change intervals. Clueless service and parts department was a little annoyed. It was a 'lifetime filter'.
There are particle count UOAs comparing the fluid with and without the filter. Ford is pretty silly to say its ineffective. Typical goofy tech writers and engineers creating fear via TSB. The procedure has changed doesn't mean that the previous was ineffective. But, they'll create fear and add to the anti-filter scare crowd. Obviously what Ford meant to say, is that their catastrophic transmission failures require more than just a filter. The techs weren't cleaning the ATF coolers or properly removing the old, loaded with wear, ATF. A machine was created so that the tech can work without thinking. Connect and push button. Sit back and say oooo aaaahhhh!