Rattling noise in Bosch WFK2401UC Compact Washer on spin
I found the problem. Indeed it was change in the washer. I removed the lower trim panel, drained the water out (there is a small hose with a cap), then removed the cover for the pump. Out fell a penny. That's right, a single penny made all that noise. The edges of the penny were silver from rolling around in the pump area. What uncovered this process for me was the manual detailing how to clean the pump:
https://www.manualslib.com/manual/19311/Bosch-Wfk-2401.html?page=19#manual
What a relief! Machine works great, no issues or noise now!