Interesting question. I suspect the liklihood is that many of these aircraft (especially a Spitfire or Hurricane) will end up representing the breed’s wartime heritage – which in a sense is what they are doing right now on the display circuit.
You raise a valid point that many aircraft’s airshow history is also important. But what of the other airshow types? Your point is surely as valid for say the Rothman’s Aerobatic Team’s Pitts.
I saw a Pitts Special at the Science Museum recently – it certainly felt right in there. It had earned its place, as do many other airshow performers.
Allan