Yeah all valid points.
But there is some stronger argument in updating the Magic Mouse and Keyboard these days, due to one changed reality: both the keyboard and mouse are supported in iPadOS. There could be incentive there to make the more compatible, like integrating the TouchID function.
"More compatible" .... what in the world does the shape ( not the function, just purely form-over-function) of the charging port on the keyboard have to do with being compatible with the iPad.
It already is.
Magic Keyboard to an iPhone.
" ...
ou can use Magic Keyboard, including Magic Keyboard with Numeric Keypad, to enter text on iPhone. Magic Keyboard connects to iPhone using Bluetooth®.
...
Note: If Magic Keyboard is already paired with another device, you must unpair them before you can connect Magic Keyboard to your iPhone. Do one of the following:
..."
On iPhone, use Magic Keyboard (including Magic Keyboard with Numeric Keypad) to enter text.
support.apple.com
unlike most of the other 'sane' bluetooth keyboards on the market, you have to decouple the Magic Keyboard from the Mac (or anything else) before you can couple it to the iPad. But it is just as bluetooth keyboard. Many on the market can handle 2-3 different system connections. That is a 'feature' thing; not a compatibility one.
A redundant biometric sensor isn't critical. ( There are some Macs with wake from sleep issues with the TouchID keyboard ... Apple should work out the bugs first, before adding duplicative sensors. )
The main target for the keyboard with TouchID is systems that don't have any biometric sensor.
Magic Mouse
already lists iPads in 'compatible' section of webpage.
Apple Store Search Results
www.apple.com
So does Magic Trackpad
Apple Store Search Results
www.apple.com
Don't forget about the Mac Studio and Mac Mini too; though they're not in the box, Apple recommends them when buying on the store. For the Studio and Pro, they sell the black one.
Apple is so busy trying to sell even more upscale "Magic Keyboard (for iPad)" that they really just don't try to mention the more normal "Magic Keyboard" that they overload and clobber the name 'Magic Keyboard'.
"Magic Keyboard "
iPad keyboards provide a great typing experience, full-size keyboard, and durable protection for your iPad.
www.apple.com
and
"Magic Keyboard"
Apple Store Search Results
www.apple.com
( Compartibility there explicitly goes through lots of iPhones/iPads/Macs . but also older before Apple launched into this name overload mode. )
But again 'compatibility' where? Studio and Mini have USB-A and USB-C sockets already. They don't use either for power. ( none of the desktop systems do. )
Magic Keyboard with Number Pad
Apple Store Search Results
www.apple.com
currently comes with a USB-C to Lightning cable. If it shipped with a USB-C to USB-C cable the connector on the Mac side of the cable is
exactly the same. Nothing hardware wise on the Mac needs to change in the slightest.
Honestly nothing really needs to change at the protocol level either since the charging on keyboard/mouse/trackpad is all USB power protocol standards anyway and USB 2.0 data transfer (where that works). The 'drama' here is
entirely form over function. It is just the physical shape of the socket.
Apple's 20-30W power bricks are all modular. The USB-C to Lighting or USB-C to USB-C doesn't mean changing the charger at all. It is just a cable.