TeNi seems very likely indeed.
He has the very characteristical voice you hear in a lot of Te doms. Quite close of Peterson in that regard.
And gamma over delta seems pretty obvious.
He is all about what is reasonable, what make sense and what doesn't. Working and producing insights to grasp something of the Zeitgeist.
He might seem to be "doing Si", because of the nature of his topic, but history isn't just Si, and what he is saying is never JUST about Si either.
He isn't trying to rectify the Archive or to set the Record straight. When asked about this, he immediately refers to serious historians who do an excellent job with it already.
It's other people's job. Explicitly.
He denounces an instrumentalization, the exploitation of history for ideological purpose.
What is at stake for him is the continued possibility of comparing and contrasting, the very right of thinking.
It seems consistent with Si polr imo : he is trying to protect the Te and Ni legal and moral metaphysical sphere from the invasive growth of a diseased Druid Tree.
Very significantly, he presents the oppositve views as an "accumulation" and a "proliferation" of "nonsense".
Which is probably an example of the "Canary in the coal mine" effect. He knows "bad Si" when he see it, and he can't ignore it.
Also, his idea that "the unicity of the nazi holocaust isn't something you can prove" definetely sounds like Si polr to me.
From an Si perspective, every historical fact is unique, trivially, and it's precisely because they are unique and singular that taxonomies and categories are needed.
The issue here is the moral "special plea" that is derived from this uniqueness. Not the uniqueness itself.
There is a huge difference btw between his defense of the free speech of negationists and Chomsky's one.
Chomsky is doing it the "voltairian" way : "I disapprove of what you say, but I will defend to the death your right to say it"
He is Si dom. He isn't afraid the Druid Tree will die and become cancerous anytime soon. He knows that the Tree is immortal already. So there is room for "tolerance".
Finkelstein on the other hand is reacting to an immediate moral danger at the heart of the Zeitgeist. And that's Fi seeking and Se agenda imo.
I also agree he is quite withdrawn energetically, but i'm not sure yet if it's due to a Ni subtype or to a shadowing factor.
He does seems to be unignoring Ti quite a bit so the latter is quite likely.
tbcd.