That was, quite likely, the worst season finale I've seen in quite a while. It stretched credulity to the breaking point, then stomped on its bones until they were ground into powder. There were a few redeeming qualities--I sure as hell am going to miss Ash and the Enterprise looked nice, even if it was the worst case of fan-service in quite a while, narratively speaking--but the writing was largely horrendous, the redemption of Burnham still undeserved, and the ending of the war was...silly. Squaring it with canon is difficult, but not impossible. But it'll take a lot of contortions to do it. The war seemed to've been too disastrous for the Federation to have it barely mentioned at all a decade or so later. Twenty percent of the UFP under occupation?
The lifespan of L'Rell should've been measured in days or weeks. A species that can, somehow, transplant entire organs from one species to another and overlay the engrams of the "donor" onto one of their own without creating an inchoate mess somehow cannot find a way to separate L'Rell's hand from her body, maintain it long enough to deactivate the bomb, and dispose of this farcical mess? C'mon... Either the Klingons are absolute geniuses at medical technology or they're complete klutzes. That twenty-three of the twenty-four houses couldn't've come together to take her down is just silly.
Or, forget about the genetic lock. Just find the bomb, isolate it behind a field, dupe the signal and remove it from the planet. Easy-peasy.
The writing in the last three episodes has been absolutely abhorrent. What happened to all the nuance? Speeches from Burnham when everyone stands up like some kind of ABC Afterschool Special? For this we got rid of Lorca? I gave it five and that was generous.
I do look forward to Season 2, but...they need to seriously clean house with the writing team. It was a chaotic season, with more missed opportunities than you can shake a stick at.