You need to read up on this subject. No self-respecting showrunner would come into the writers’ room one day and say, “Listen, there’s just too much complaining about the redesigned Klingons and the D-7 which didn’t look anything like the one on the old show… I mean, should we just change that back? We can say, I don’t know, that it’s no longer the time of war and now there’ll be a new D-7 representing unity.”
That would just be weak, and we can hope it’s not how the conversation went, but either way the end result still feels like backpedaling, not like an inevitable story point: an invasion of TOS Klingons perhaps (in their simpler ship designs). Because of the way DS9 and ENT handled the issue, story canon says that smooth-headed Klingons have to be somewhere, and DSC still follows story canon.
See also
this interview with Ron Moore in reference to his own shows: