"Redeemable" has never been the criteria in my definition of obsolete. I know lots of casinos that will redeem obsolete chips.

I see nothing in this article that implies a connection between "current inventory" and obsolescence. The US Government decides when a coin is obsolete. We don't. The nice thing about US Currency is, the government will clearly tell us all when they obsolete a coin or bill. Is the Sacajawea dollar obsolete?