Thank you, kind of odd they have an option for "Remove Channel" which returns success and yet does nothing...
You have a point there, what's the use of such deletion - other than creating orphans?!
Btw please note even if you persuade Roku to remove public channel from the store (which is your right, to withdraw), that does not mean the channel will magically disappear from people's devices - just like this is not the case with iOS and Android apps. To "actively discontinue" a channel, you'll have to release an update, a new version that will show end-of-service banner instead of the old content. And since updates are automatic on Roku, it will quickly infect the players