That's what the oil/tranny filter is for, to catch small debri, and why would you leave the "metal dust" in the tranny for 30,000 miles if this was the case? Why not change the tranny fluid at say 1,000 or 2,000 miles?As to fluid I have this to contrinute - a new engine or transmission, for the first many miles, 'makes metal'. In other words as the parts wear together they rub off tiny bits of metal until the mating surfaces are matched. This happens with all metal-to-metal componants, and there is nothing wrong with it. However you don't want this metal dust sitting in your fluid, turning it into a grinding compound. It is far mosre important to change your fluid early, and then go for a prolonged period, then to just leave it until scheduled. Thirty thousand miles and I'd change it, then not worry again until 100,000 becuase I have the metal dust out of it. Same with an engine.
Not trying to be a smart-azz really a serious question.