When will I get Discovery GO on ROKU?
I subscribe to one channel and that is DTVN .

The combination of Discovery and DirecTV Now doesn't authorize on Roku, Apple TV, or Fire TV. I haven't checked any other devices.

So, it's entirely up to DirecTV Now and Discovery to decide to allow authorization on Roku or any of these devices.

Thank you for the information.  Patience will be the best cure I hope.

Could not activate Discovery GO. The only streaming service I have is DTVN and they do not subscribe to the GO 
part of Discovery.   Maybe someday.
Thank you for the inquiry.