I think the general assessment that East vs West had to be cancelled is a fair one, it doesn't meant that we wouldn't still love it, it just means we might have been too few in number.
A cold war game in the style of paradox would need to work out specifically what it wanted to do before it started, and whether it would be fun.
Fun bits: Everything blowing up - I agree that this shouldn't be easy / possibly even doable, but how many of us got a bit giddy when the EvW clip came out of a nuclear attack? These was in the HoI3 days, it looked impressive for a "mod" of an existing game. An endgame scenario might be nice, but it shouldn't be easy to get to. That would hopefully lead to a "I don't want this to happen because I've invested in my game" feeling to encourage preventing endgame happening.
Converting smaller nations to your ideology: Clearly this would be the most important part of the game in terms of how gameplay would work. If we're working on the premise that nuclear Armageddon is intended to be avoided, and 2 or more factions are playing out to beat the other without either destruction of one side or mutual; this is the way to go. I think this would require a IR/Vicky pop situation, doesn't have to go deep as Vicky unless it wants to, ideology by region might be enough (and then have factors relating to region output influence from events whether ideological support goes one way or the other). For democracies, the obvious answer is elections - I think historically accurate national and presidential elections, possibly governorship ones too would be reasonable to track. In other nations, a similar system would have to be installed, perhaps a military junta system where generals and admirals vie for power internally through more interpersonal relations with each other would be good. I don't know too well how later soviet system works, I'm guessing soviets wouldn't be greatly historical for them but there might be alternatives in collective leadership scenarios.
Big and small play: Factions I think should be set, whether that is 2 + neutral / China or 3+. Although its always nice to have it have the ability to be modded. Big nations should be more about influencing small nations or controlling states already in their sphere. Obviously the Soviet Union is a clear leader on that side, but it gets more complex for the other. United States yes, but a middle ranking for nations like UK, France would also be good. Smaller nations should be more practical, these are the ones fighting the wars - and should be more based on conflict mechanics. It should be possible to avoid war mechanics for the bigger nations as the point is they don't directly fight - although perhaps support roles or minor combat should be available.
Not so fun bits: Dangers of boring play. I think any game can have this. Start CK2 in Iceland on the first start date? Don't expect much to be going on. There will be nations in any cold war game that is the same, but people meme play everything anyway, we can still have silly games of random island territories becoming major nations for a laugh, as long as its not typical of the AI. Smaller nations need internal politics, even if most of it is influenced from outside, there should be ways of still making a difference. Border conflicts can also be a thing to keep things busy. Bigger nations, I think would need to rely more on the bigger game, as wars will be no existent - an IR/CK model of character interaction would probably be the minimum.
anyway, that's just my thoughts of what I would do.