I also just did the syncromesh fluid swap for the first time(work for GM , got the stuff for cost + 10%)
Did notice a incredible amount of "swarf" in the drain plug [:0], but havn't noticed any new seepage yet....mind you it's only been short trips so far, the 300km road trip is coming in two weeks......
Probably flush out the trans again over the winter,(i don't plan on doing a heck of a lot of milage this year) will be curious to see if there is the same amount of swarf this time.
Ron.