Manual Transmission Fluid - Ford Focus '02

My Hondas ('75, '81, '88) called for fluid changes every 30k miles.
My '06 Matrix doesn’t call for fluid changes, but the C59 5-speed has a history of early bearing failures, so I changed it at 21k just to see what’s what and the oil was dark with a metallic sheen.
So I feel better about it at least.
2000 miles later I went to a dealer for a recall and the service writer told me the trans fluid was dirty and I should get a flush(!).