Good day cheerily999! I am glad to be able to provide assistance to you today. I understand that you are checking with regards to the Microsoft Natural Ergonomic Keyboard 4000 if it has been discontinued. If you are referring to the old model of it then it has been discontinued and you can check out the link below for reference with regards to the newer model of it.
https://www.microsoft.com/en-us/d/microsoft-erg...
Regards,
Paul R.