Nobody needs to worry about the next series following any old formats that were tethered to the broadcast formula, because space opera can't survive on broadcast (and the survival of broadcast itself is in doubt - unless it evolves into some kind of live-events forum, of ad-zapping-proof sports, news and reality game shows).
Think of Star Trek
as a species whose ecosystem has been destroyed by climate change or a comet. The species is doomed, unless it evolves to thrive in one of the new ecosystems that have emerged. 22 episodes a year is an old-ecosystem quality. Episodic structure is another. Fortunately we're talking about an unusually adaptable species.
The next series will be a big departure from what we've known before, more different from the previous series than they are from each other. You can make educated guesses about what form it will take simply by looking around at the ecosystems where it might thrive and seeing what already thrives there, such as the complex political machinations of Game of Thrones
or House of Cards
, or the gruesome violence of The Walking Dead
And then there's the issue of not expecting the species to evolve from a bird into a tree. Star Trek
does have certain core values it needs to hang onto. Not going hard-R is one of them. Having some sort of spaceship travel element is another. Starfleet as the central principle is a given.
These are not particularly limiting stipulations. We still have at least two centuries and a whole galaxy to play in and I guess technically two different realities as well.