That's not quite right though (and I fault their PR people for not explaining this). The token can be exchanged between any party on the blockchain (which afaik is not JPMC-only). You only need to transact through JPMC to exchange the token for USD.
JPMC still controls who is allowed to exchange tokens. Which means that you still have to transact through JPMC to exchange tokens as JPMC controls the blockchain.
If somehow they don’t retain majority control of the blockchain, then you technically don’t have to transact through JPMC but I don’t see that happening.