I would agree that it's not that useful to have it's own forum. It's not even really that well-defined, as you can be seen in this thread. For some people it's more about the gear, and for some people it's more about the terrain. And even if you agree about which, you probably won't find universal agreement about how to categorize the different options.
Unlike Brian25, I consider bikepacking to be a subset of self-supported touring, and "credit card" touring to be the alternative to self-supported touring.
Currently I run some combination of rear panniers, a handlebar roll, a frame bag, and sometimes some fork cages. Most of that is considered bike-packing gear, but the panniers are generally not. But most of my trips also involve a fair amount of pavement. I did do a week or so largely off-road with a standard bikepacking set-up (saddle bag instead of panniers), but in that case "off-road" was the GAP, a pretty standard touring route for all kinds of self-supported and credit card tours. So was that bikepacking? I don't know. Riding the C&O canal on a later trip felt closer to what I think of when I hear "bike packing," but there were still plenty of standard touring set-ups on that trail (and I was back to hybrid, rear pannier set-up), so was that bikepacking?
Personally I think bikepacking is more about where you ride than it is about how you carry your gear, but talking about bikepacking gear as a subset of touring gear can be helpful. To me, though, actual bikepacking would be: fully supported, mostly off-road, with few available facilities. That is a pretty limited subset of touring, and there are lots of places for overlap with the other types of touring, and lots of overlap in gear, preparation, packing, etc. Not sure what would be gained by trying to put bikepacking discussions in a separate area.