Isn't that a bit of a tautology? "If I expand the definition of the word 'troll' to include 'authors decrying trolling' then authors who decry trolling become 'trolls' themselves."
It's not an exceedingly convincing statement to me personally.
Though you've used one of the adjectives I think best describes the nature of 'trolling' and that's "bad faith". Personally, I feel the most useful definition of 'troll' is someone who argues/antagonizes/insults others not because they are trying to make a point or start a conversation, but merely to provoke a negative response.