Well, Tim Cain said in an interview (after he already left Interplay) that China started the great war. That never really made it canon. Canon explanation in-game was that nobody really knew who fired a nuke first. And at least one Interplay co-creator said that was very much by design. And that makes the new series mention, the actual first canon explanation of who started the Great War.
I agree about ghouls, although I imagine they did correctly figure they needed an explanation for why some went feral and some did not. And I'll add that the chicken-loving "doctor" having a miracle inhalant that turns someone into a ghoul instantly... that kind of bothers me too.
But yes, show's still great.
Just some counterpoints...
First, that Vault-Tec is ultimately responsible for the war -- either by false flagging or manipulation -- whether or not they detonated the first nukes, is actually one of the oldest fan theories in the entire IP. Dates back to Fallout 2's release, in fact, when the PoseidoNet terminals revealed Vault-Tec was actively part of the Enclave. It's hardly a retcon to confirm one of the oldest fan theories in the franchise, based directly on implications from information available in-game.
Second, even if anything about the "Doctor Strangelove" scene could be considered confirmation. All that was said, ultimately, is that if no governmental body launched first, Vault-Tec would. That preserves the ambiguity of who actually did it, while cementing Vault-Tec's nefariousness in the minds of viewers who may not be as familiar with Fallout lore as long-time fans.
Third, exactly what special sauce leads a human to becoming a ghoul instead of, you know, excreting their liquifying internal organs through every orifice as is wont to happen in cases of severe acute radiation sickness, has never been clearly identified in the franchise. Neither is exactly how or why ghouls go feral.
Closest in the former case is some unknown combination of genetic and pharmaceutical factors, combined with potential FEV exposure, and fatal radiation dosage catalyzing the transformation. Closest in the latter is just neurological degeneration over time, akin to Alzheimer's, Huntingon's, Parkinson's, and the like exacerbated by prolonged severe radiation exposure...as is likely to happen to ghouls who spend prolonged time, isolated, underground or indoors. What ghouls say in the games about forestalling feraldom -- staying social and mentally active, getting outdoors as much as possible -- are just common therapies today in the real world to help people with neurological degenerative disorders delay symptom progression, adapt, and preserve morale/quality of life.
The big theories I've seen since the show came out, is this "ghoul drug" is a combination of RadAway, powderized Rad-X, and/or some hormone or neurotransmitter still produced by non-feral ghouls. The drug matches the appearance of RadAway even if the intake mechanism is inhaled rather than intravenous, and its effects seem similar to Rad-X. Cooper resorts to cannibalism when his supply is destroyed -- and the dealers at Super-Duper Mart have to be keeping a captive population of non-feral ghouls for some reason. Two plus two equals this might be some chem ghouls produce naturally until a certain point in their lifespan, tapering off naturally until they go feral, which can be supplemented by (inhaled) "hormone" therapy.
Sure, it's fanwank for now, but at least it's sensible fanwank. Cooper not actually presenting any symptoms of going feral is another story entirely, but we'll see what happens in season 2.