I don't know or care about his type but this was very well thought out. I have a lot of experience with ILI irl, long term, and I agree with your take on them.Why are people so convinced he's any kind of NT anyways? He studies human thought and behaviour, he delivers the material in an emotionally expressive way, everything he talks about is ethical... why would he not be an ethical type?
ILI’s concept of morality is nowhere near as sophisticated as what Peterson demonstrates. ILIs usually have some basic ethical values that they follow and then if someone crosses their values they go on a bitter tirade and maybe they will seek retribution. They don’t have complex mental landscapes for morality. Even if they did, they would have trouble expressing those kinds of thoughts because it resides in the very introverted realm of Ni/Fi for them and Fe polr gets in the way of them clearly explaining why they feel a certain way about something. ILIs do not have the level of understanding of other people that JP shows nor do they have a real interest in discussing people this way, especially if the person being discussed has no relation to them. An ILI would not spend their time reading the diaries and autobiographies of mass murderers trying to understand why they did what they did. However, it is common for an IEI to seek to understand the behaviour of others.
Jordan Peterson has demonstrative Fi. His 4D Fi is used for other people, not himself. He thinks mainly about other people’s/ society's beliefs and identity, not his own as an individual. As I said before, he is concerned with universal morality (OBJECTIVE ETHICS) that underlies all of humankind. (That’s what Maps of Meaning is about). Simply discussing morality is not proof that someone values Fi. The person would have to be espousing their own morals and using these morals to judge the world around them. He doesn’t do that. When it comes to his own subjective views, he is clearly analyzing, not making moral judgements.
Also, ILIs are possibly the most monotonous type. JP gets really enthusiastic in his lectures sometimes to the point of yelling and gesticulating, and he breaks into tears a lot when talking about emotional stuff. Even on his official 12 Rules For Life audiobook he is crying while reading near the end of the book. This would be all very unlikely behaviour for an ILI.
Where is the Te? Where is the procedural logic and business acumen? He gives away his lectures for free on the internet. He does long livestreams each month to talk to his fans and followers and answer questions. What benefit would he get out of that in terms of productivity or financial gain? (I'm sure it helped him sell his book but that seems like a side benefit rather than the entire purpose of everything he does). It seems like he just likes connecting and discussing with people and building up a following.