Although the Touch ID sensor on the new Magic Keyboard is compatible with all M1 Macs, including the new iMac and the 13-inch MacBook Pro, MacBook Air, and Mac mini last fall.
Apple has confirmed that The Touch ID sensor will not be compatible with the new iPad Pro, although the latter is also furnished with an M1 chip.
The new Magic Keyboard can still be used on iPad Pro and other devices, like Intel-based Macs, but these devices cannot use the Touch ID fingerprint function.
Apple will give three versions of the Magic Keyboard, including the standard version with Touch ID, the standard version without Touch ID, and the extended version with Touch ID and numeric keypad.
Moreover, according to Apple, the new Magic Keyboard will only be provided with the new iMac and will not be sold separately, at least initially.
The high-end 24-inch iMac will provide a Magic Keyboard with Touch ID for free, and the basic model must be purchased separately.
(Via)