"Ron Olesko suggests that meanings gradually change...and so they do - but the older meaning meant something, and just because 'some' people (51%?? how do we count?) don't care to follow that older usage, it doesn't follow that the older one is now 'meaningless' or obsolete!

If 'folk' or 'trad' meant a narrow set of referents originally, and now some consider the words 'convienient' to mean a much broader set.....what, I ask for the 27th time, are we to call that older set when we WISH to refer to the narrower meaning? "

I think we call the older set folk, and we call the newer set folk. There is plenty of room, no matter what definition that you use, for both. I don't think anyone has suggest that the "older usage is either meaningless or obsolete - it has simply grown.   Grab a dictionary and look up the definition.