I understand the reasoning but still think it's quite wrong. The Purist edit is a modification of Revisited in the first place; moreover, the differences between the Purist edit and Revisited proper are far smaller than the differences between the Purist edit and the original, both in scale and quantity. If Revisited qualifies, it is very surprising that the Purist edit does not. I agree it's sensible to have clear rules and a definite line, but those rules would have to be very odd for two very similar edits to fall on either side of that line.