If I buy from an Apple Authorized Reseller, do I get the same monthly installment deal on a MacBook Pro

No. Some Authorized Resellers have their own financing plans through other companies.

Also see the following from Apple Card - Monthly Installments - Apple

Whether you shop on apple.com, on the Apple Store app, or at an Apple Store, simply choose Apple Card Monthly Installments as your payment option when you make your purchase.

We are not Apple so you can't get an "official" answer here. However this part of the article you linked:

To receive a 0% APR installment on eligible products from apple.com, the Apple Store app, or an Apple Store, you must choose Apple Card Monthly Installments as your payment option at checkout.

suggests it does not apply to a reseller. You can ask the reseller but they probably have a separate non-Apple plan if any.