New iPhone Air camera not working, seeking replacement

Apple will at their discretion either repair or replace the device under warranty for free. Apple Care+ extends this option an additional year and offers additional damage events for a reduced fee if you choose to buy it but there's no requirement to do so, and manufacturing defects are still covered under warranty without buying Apple Care+.

Camera issues will usually result in a complete replacement device.

The replacement will either be a refurbished model or a new one again at Apple's discretion. Considering the iPhone Air is barely 4 months old it's unlikely they have any refurbished units yet, so likely a new one.

New or refurbished devices used as service replacements will receive a model number starting with the letter N, not F.

The F indicator is only used with refurbished models that get sold on Apple's refurbished online store.

The question is, why do you think getting a replacement will prevent you from returning it to Rogers?

Have you asked Rogers?

Rogers should take the replaced iPhone at the end of the term. You can further prove the replacement with Apple's own Service receipt that matches the new iPhone model, serial and IMEI to the replacement iPhone's model, serial and IMEI.

If Rogers denies this, you can contact a manager at your local Rogers Store or try to go to a different one.

Apple will NOT change the model number of your phone if they repair it. You're referring to a Refurbished phone, which is sold as Refurbished. As to whether Apple will fix or replace your iPhone, you'll need to ask Apple.