I don't like spending this much time arguing against campism but they just keep talking at me.
No, while the term "tankie" is used diversely, and some probably use it as you described, the essence of the term is simply a supporter of old school authoritarian "communism". Think Marxist-Lennist ideologies as experienced under and in the post-Stalin soviets. Tankies love to downplay N Korea's crimes, as if if denouncing both South and North political establishments is impossible.