How about just releasing a new keyboard like they did with the new iPad today? They could give people the option of using the existing magic keyboard or using the new folio keyboard (which looks much nicer btw).
And of course the new iPad kept compatibility. Its the same iPad they've had since 2018.....
It wouldn't make economic sense to offer two different keyboards with touchpads for the same model, they would cannibalize each other. The Magic Keyboard has obvious advantages over what was released for the iPad today.