Very interesting... .
I've followed this board and have not seen this mentioned before...
our 08 5500 now has 23K miles and we've had no problems... could there be a re-route in the wiring your dealer isn't picking up on... . and just replacing the harness... .
I'm suggesting that you might do some of their work for them... to save you down time... . go look under the hood of an 08 and see if there is a different routing of the wires or a different harness that does a better job protecting the wires...