When will the Roku Channel add more episodes of Hee Haw?
Best way to be alerted when new episodes are added to an installed channel is to use the "My Feed" feature within Roku. Search for a show (from Roku Search), then select "Follow on Roku".
Hard to say when new episodes and seasons get added and removed from the Roku Channel. Another benefit of the My Feed is that it will also alert you if a particular show or movie you are following has been added to another channel (Tubi or the like).
And you can always request more episodes, or another means of being alerted (e.g. email):
https://community.roku.com/t5/Suggest-a-Feature/bd-p/Wishlist
Whomever owns the rights to Hee Haw seem to make only a limited number of episodes available. The show ran for more than 20 years, yet I've only been able to record 80 episodes over the air. They just keep repeating the same episodes over and over. It likely doesn't matter how much Roku might like to have all episodes. The content owners simply aren't making them available.
Requesting episode aired on 09/28/1985, guests on the episode are Reba McEntire, Osmond Brothers, and the Tennessee Moonshine Cloggers.
Uh man! They removed Hee Haw from Roku!
Circle All Access distributes Hee Haw, Grand Ole Opry, Petticoat Junction and a bunch of the old country/western shows. (https://www.circleallaccess.com/ and https://www.circleallaccess.com/watch-circle/).
You can still catch episodes of Hee Haw on Roku Channel ch.317 which is Circle All Access. (Live TV rather than on-demand episodes).