"possibly" research? Sorry, but the attitude that research -- i.e. the consideration of history and the big picture -- might "possibly" be a part of longform writing is like saying math might be a part of good physics theories
I see where you are coming from, but some long-form writing is itself the research. Paul Graham (IIRC) said that his essays were a way of exploring ideas. In some of my writing, I have this to be the case also. And then, of course, there are writings where the actual banging words out is a tiny sliver of the total time taken, when compared to the research component.