You've asked for it and Sound Devices listened. The upcoming CL-16 control surface was originally slated to only support the 888 and Scorpio mixers. Now Sound Devices has announced they will be working towards a Firmware update on the 833 to give it support for the new control surface as well. Note this doesn't guarantee that the CL-16 and 833 will work together at launch, but it is an eventuality.

Until support is finalized, there are other control surfaces currently compatible with the 833, which you can find on Sound Devices' 8-Series FAQ. For any updates to information about the CL-16 see the CL-16 FAQ. The CL-16 is currently targeted to release in Q2 2020.