Ah, I see. Yeah, they're very measured in their approach. Right now they want to court the content providers, and not including other 'over-the-top' content such as Tablo is likely a part of the bargain they're making with them.
I would hope they expand access over time. HomeKit, for example, also started out with a very restricted set of partners. But each year, they keep loosening up, bringing more partners into the fold, and being less restrictive with the API.
So maybe after Apple has all of the major providers on board, it can afford to open up access to that API. After all, the whole idea with the TV app is to be provider-agnostic, so I would assume that there isn't anything about Tablo that is asymmetric to Apple's long-term goals.
So yeah, I don't think a new do and kicks will do anything. "It's not you, it's me" Apple would say. Besides, just be yourself!