For reference, the IEEE 802.15.4 spec is ~800 pages long. 900 pages does sound like a lot considering that Matter (AFAIK?) doesn't directly spec any hardware or transport details - those being covered in 802.15.4 and Thread.
Granted, we should remember that those 900 pages include base details that, probably, CSA are not planning to change in the foreseeable future. They need to be very thorough.
To answer your real question: device manufacturers will likely use the Matter SDK. It would be a huge undertaking for a smart-light manufacturer to re-write all of that code from scratch!
Granted, we should remember that those 900 pages include base details that, probably, CSA are not planning to change in the foreseeable future. They need to be very thorough.
To answer your real question: device manufacturers will likely use the Matter SDK. It would be a huge undertaking for a smart-light manufacturer to re-write all of that code from scratch!