So first, you're mixing it up with "e.g.", but that's not really important. It doesn't matter if "taunt" was just an example, it's still true that Nasus, Garen and Mundo have pretty much nothing --neither taunt nor anything else-- to hold aggro.
Second, I'm not "operating under my own assumptions", and I never said that "tanks are required to be primary initiators". Even in the post just above, I also mentioned peeling against an Assassin and disrupting the enemy carries after THEIR initiation. What I did say was that Tanks are required to provide control over the flow of a fight, and that's not my own assumption, that's the definition used by Riot, which is a very logical adaptation to a PvP game from the original definition coined for PvE RPG games. Never have a Tank dealt large amount of damages, that was never their purpose, and what follows from that is that a champ who primarily provides damage is not a Tank at all, not "a different kind of Tank", even if it is a durable character.
Finally, I'm not digressing from the point where I started participating in the conversation, which was already 6 comments down the tree. I obviously agree with the original topic about "Tank Assassins", and I just made a shot reply to correct a factual error. So yeah, you can say that I'm not participating in a debate, because I am not. There is nothing open to debate here, I'm not providing my own opinion, and it was never intended to turn into a debate.
P.S.: regarding i.e. versus e.g. you can have a look here http://grammarist.com/usage/ie-eg/ or check another dictionary http://www.collinsdictionary.com/dictionary/english/ie_1#ie_1__8
Even in your own link, if you read the real definitions (the part in pink) it says the same thing. There is simply an error in the "Note" part under the first definition, which is not consistent with the rest of the article, not even with the examples given at the end that really are "all inclusive lists".