Defining later noirs is an ongoing challenge. It seems a question of subject matter (content), themes, character emphasis, and tone (flavor, atmosphere, mood, how it makes us feel). Defining the main differences between classic noirs and later noirs is another challenge, even though they are all noirs.
Another challenge in the back of my mind is to make a list of the ones I like best, which are hopefully also the best ones. But that requires quite a lot more viewing and seeing quite a lot more films than I've seen.
Television noir is a huge area that I simply don't have capacity to get into. It's good that this forum is going into that. Gordon's work and collecting is exemplary. The talent alone in these shows is stupendous.
It's good to have Don exploring foreign noir in depth. French noir is a constant through the years, but with ongoing changes in style. The same with British noir. Other than that, the ball seems to pass to different countries from time to time, and each one has its own tone. Hong Kong noir that comes in around 1980s and 1990s differs from Korean noirs in the 2000s.