I assure you it was a passing fancy.
Well, I don't need to wonder any longer. On Tuesday, I used a $20 bill to buy a 4 trip Charlie Card (why did they name a transit pass after someone who was lost forever in the subway?) for $5 out of one of the spanky new machines. The machine spit out the card, and then proceeded to vomit my change in the form of 12 Sacagaweas and, just as an added dig, 3 Susan B.'s. It was kind of like winning at the slots, except with a deep-seated feeling of WTF?? replacing the winning euphoria.
I've spent them at this point, but it required things like joking with the young woman who made my au lait about the T's infernal plans and later stopping to explain to the parking garage attendant what the coins were and how they had been issued from the machines downstairs.