I don't want to get into the debate of if or if not, but only to relate what I know with my experience. It doesn't by any means mean, well ...any thing.... Just putting it out there
I bought a 280 Handi with an extra 204 barrel at a local gun shop that had an Sb-2 dated back to around 97 or 95... I don't have it near at the moment.... I do not believe the 204 to be the original barrel, as the chambering hadn't been availible yet :p , but the 280. Either way both shot fine and with no complications. I understand the warning here, but I also understand H&R being put in with a few lawsuits and NEF picking up the trail and putting a warning as they had no way of underseeing the work done prior so can only ensure what they have been overlooking.
Perhaps I am oversteping here, as I don't claim to know all the answers. But it seems to make sense. Still no harm in being careful. To each his own and warning.
-Aaron