Live-play questions are on-topic
The line between RPG-content and entertainment is unclear and constantly evolving. It's a new genre and unclear exactly what it is. Anything from from live-play, to performance-art, to entertainment show and a whole spectrum of things in-between. In future we may even have sub-genres for these shows. But all of that is irrelevant to whether this is an on-topic question for this stack.
Could these shows be on-topic at Sci-Fi & Fantasy? Yes, in fact they even have a tag for it with 3 questions. Does being on-topic elsewhere mean that it is off-topic here? No.
From our help-centre on-topic article
A good rule of thumb is to ask yourself:
Would an RPG expert give me a better/different/more specific answer to this question than a Historian, Geographer, etc?
If yes, then feel free to ask it here.
In this case I believe the answer is yes. An RPG expert is more likely to give a more complete/specific answer to a question about a live-play RPG than a Sci-Fi & Fantasy expert would.
Questions about live-play shows are a combination of mechanics, lore, social dynamics and plot that is unique to the RPG genre. Answerers unfamiliar with RPGs may address only some of these aspects while missing key details in another. Thereby giving a weak or possibly entirely wrong answer.
Live-play RPG questions are fundamentally RPG questions and therefore should be on-topic at RPG.SE.
Note: This does not extend to questions about the cast, companies or other related but external elements that go into RPG live play, only the content that appears as part of the RPG show.