The more subscriptions people need to access the content they want, the more likely they are to pirate it instead.
Everyone is talking about "Netflix-like" and "Steam-like", while forgetting that Netflix and Steam grew big not because of their subscription plans, but because they were a single point to access all content.
Keep in mind that Sega isn't just a developer, but also a publisher. They are relatively big in the strategy genre, for example, as publishers of the Company of Heroes, Dawn of War, Total War, Valkyria Chronicles and Endless Space series. They are also PlatinumGames' publisher, own Atlus, etc. pp.
This doesn't mean they are necessarily big enough to be able to successfully pull this off, but we'll see.
If game companies are going to do this, then they should just sell their content to Netflix or Microsoft and cash in on that licensing revenue while not having to do any of the work.
I do not understand why companies are choosing to make their own streaming services when they are just money pits that provide minimal benefit.