"trolling" in this instance seems to be a nicer way of saying "misleading to create attention". It's hard to deny that "look at how garish these beautiful statures originally looked" created a lot more attention than a theoretical "Roman statues looked pretty nice, but with paint"

It's an unsubstantiated theory, but the author does go out of their way to say that this might not even be objectionable, if it happened at all