I spoke to an apple specialist and they said that the magic keyboard is covered under Applecare+. I bought my iPad and then added the AppleCare+ o the day it was delivered, and Apple did confirm via chat that the magic keyboard is covered.
this is from my AppleCare+ agreement:
The Plan covers the following equipment (collectively, the “Covered Equipment”): (i) the Apple TV, Apple Watch, HomePod, iPad (including an Apple Pencil and an Apple-branded iPad keyboard purchased for use with your iPad, referred to as “iPad Input Devices”), iPhone, iPod, or the Apple- or Beats-branded headphones listed on your Plan Confirmation (“Covered Device”), (ii) the accessories contained inside the original packaging of your Covered Device, and (iii) for Monthly Plans with an original Plan purchase date prior to September 2020 only, an AirPort Express or AirPort Extreme Base Station, and an AirPort Time Capsule if used with a HomePod or an iPad that is a Covered Device and purchased no earlier than two years before the HomePod or the iPad (“Connectivity Device”).