Apple knows nothing about your cards (they are all encrypted on-device), and nothing about your transaction except that there was A transaction (since Apple just sees a token that gets passed from you to the card provider).
The merchant doesn't see your real cc number, just a one-use token. So they can't track you unless you choose to add a loyalty card.
The card provider sees all details of the transaction. Just as now, and what you want.
And the real cc details are stored in dedicated silicon on a fingerprint-locked device.