There's a possibility that Mississippi, Louisiana, and Oklahoma may follow Arkansas in this decision.
Anywhere you have state governments involved, there's a possibility they will drop PBS once their contract ends.
Then you're going to have a fairly large swath of the country that won't have PBS.
They're going to have to end up making one (or more) of the larger PBS stations into a kind of "PBS Superstation", made available to non-OTA television providers. WGBH, WNET, or WETA, maybe? I'm assuming that would fulfill the requirement that there be some kind of intermediary.