Paramount originally streamed its Yellowstone program via the Paramount app for those that had a tv provider (cable/satellite/whatever) that included Paramount. This preceded the creation of the Paramount+.streaming app. For whatever internal reason, they decided to continue to release season 4 of Yellowstone on Paramount that required a tv provider account rather than Paramount+ that you can subscribe to directly. Paramount+ will likely get season 4 when it has been fully released one week at a time on Paramount.
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