I think the concept of what is "encyclopedic knowledge" needs to be made more explicit
Encyclopedic knowledge is verifiable and informative, amongst other qualities.
[[wikipedia:verifiable]]
[[wikipedia:informative]]
We're slowly and quietly amassing quite a wealth of information on how to decide what should and should not be deleted. (though I will probably now discover that one or both of these articles has been deleted!)
-Martin "MyRedDice" Harper