Joe,
The "Traditional Singers and singers of Trad" thread had drifted way off topic onto matters that are better avoided, so you were not wrong to close it, but I only saw it just now and would have wished to post something germane. Anything to be done about that?
Here's what I wished to say.
There is a distinction between the OP's categories but they overlap rather than being clearly separated.
I was recently at the "Traditional Sing" weekend at Moreton-in-Marsh. It is one of the closest approximations now existing to the "National" folk music festivals in England that used to mix traditional/source/whatever-you-want-to-call-them singers and revivalists. But the former have mostly died out. There were a few at Moreton, but one who is generally considered to be in that category, Jeff Wesley, freely acknowledges having got much of his repertoire from folk clubs, as did one of those already mentioned in the thread, Fred Jordan.
Gordon Hall learnt songs from his mother but also searched print sources for additional material. And what about Jeannie Robertson getting one of her ballads from Jean Ritchie?
And then there's this from the great Jean Ritchie herself.
sj