Naudet, Mandoble,
You are making a pretty big assumtion that the N1K2 and La7 will become unusable.
They are being fixed, not neutered/removed.
Both the N1K2 and La-7 were very good fighters, don't think that they will suddenly suck.
I also note the fact that anti-N1K2/Spitfire types continue to ignore the position of the P-51D in number 3. You talk about the N1K2 and La-7 disappearing from the list and then you put the F4U-1D and Spitfire MkV in while, with no explanation, the P-51D disappears from the list.
If the N1K2 is seriously weaker (which I doubt) then the Spitfire MkIX (of which a whopping 300 were built, 100 less than the N1K2) will take the top spot, probably followed by the N1K2.
It is clear that most people like to turn & burn. The best two fighters for that are the N1K2 and Spitfire MkIX. If those two fighters were perked/nerfed/removed I think many people would try to use less competitive turners like the Spitfire MkV and A6M5b. Once they realized that those were so out performed by the late war speed demons that they were hard to be successful in many would quit.
Sure, some would go to the late war speed demons and learn how to use them. It isn't very hard really. Some of them would decide that they didn't enjoy the BnZ approach and would quit, others would stay on.
The most common aircraft would then be things like the P-51D, La-7, Bf109G-10 and Fw190D-9.
At that point I would quit.
I like to be able to fly a mix of aircraft types. Late war speed demons would be a much worse plague than slow turn and burners like the Spitfire MkIX and N1K2.
I want to fly the Mosquito FB.VI. It can run from the Spitfire MkIX and N1K2. Against the La-7, P-15D, Bf109G-10 and Fw190D-9 it is dead. It can't run, can't dive, can't climb, and can't turn with those aircraft.