IPhone Upgrade Program and T-Mobile

I recently switched to T-Mobile and both my lines have paid off unlocked iPhones.

Are T-Mobile users not eligible for the iPhone upgrade plan from Apple since it's only showing contract-free option for T-Mobile? I would be surprised since Apple's plan is completely separate from the provider. And I really don't want to get the phone through T-Mobile, I like the idea of yearly upgrades right at the Apple Store.

Hope someone can clarify. Thanks!