Earlier quoted context omitted.
I think you're over-thinking this. There isn't a huge crossover audience for engineer blog posts and general NYT audience, and I imagine the engineering blog posts do not go through the same editorial process content on nytimes.com does. That alone makes the case for using a different domain.
I'm being a cheeky detractor of NYT here. I think "candid, engineering-style blogposts" are the future of news, and ancient vehicles like New York Times are long dead. I think the "general NYT audience" is participating in #FakeNews, and they should radically reconsider their information diet. As vivid example of this, compare James Birdle breaking the "Youtube exploitative kid videos" story way before, and in greate…
https://www.nytimes.com/2017/11/04/business/media/youtube-ki...
and Birdle's post itself links to reporting by New York Magazine from 2016. I don't dispute that his post goes into more detail, I just dispute that longer automatically equals better. Someone with domain knowledge reporting a story in great depth and a major publication reporting a simplified version for mass consumption is certainly not a new model.
I'd also strongly disagree that NYT is an ageing institution unable to adapt to this modern tech reality. John Herrman writes some of the most perceptive pieces about the state of tech out there:
https://www.nytimes.com/by/john-herrman
(and a minor quibble: I don't think the post linked here and the Youtube Kids post are in any way comparable. The engineering writeup is not news in any way, shape or form, it's just a guide to how NYT implemented something)