Besides, I'm fairly sure that DSC couldn't have been set in the Kelvin timeline even if they'd wanted to. Kelvin is the sole property of Bad Robot and its ilk. They won't let the novelverse deal with it, and so it stands to reason that they wouldn't let DSC do it either.
First off, it seems pretty clear that this series takes place 10 years before TOS in "that" universe.
But as for the quoted post: I see this a lot, but what does it mean?
These things are determined by contract. I gather JJ/Bad Robot own the right (by contract) to make a certain amount of movies within a certain amount of time with (likely) exclusive use of a certain set of characters. And maybe the USS Enterprise.
They obviously DON'T own the rights to the Star Treck franchise exclusively, or there couldn't be a Discovery (without their approval/contracting with JJ/Bad Robot).
And they don't own the exclusive intellectual rights to, say, Klingons or the character Sarek, obviously, which are creations of the TOS timeline.I would assume they legally 'own' or could prevent someone else using things and characters they have created in the three movies.
But in a court of law, I'm not sure how they'd own rights to an ill-defined "timeline." Seems to me it's more something for fans to discuss and debate rather than an actual intellectual property (like the characters Kirk and Spock, the Enterprise and the 'universe' in which Star Trek takes place) that can be protected, sold or contracted out to another entity.