When I read the letter, I had two thoughts. The first was that it was objective of them to list several choices as approved brands. Among them, Castrol Syntec, my oil of choice.
My second was a curiosity of the "why" of it. It occurred to me that perhaps this FSS pre-programed schedule was starting to show a higher repair incident level on items which could be related to wear factors caused by "dirty" oil.
I have ignored and will continue to ignore any recommendation that advises me to go 10K mi between oil changes.
That is why I don't need a full synthetic oil in my engines.