You yourself take considerable liberties with melody and phrasing (if your youtube postings are representative), so why are you up there on that hobby horse telling the rest of us what to do?

Messing with the words is what we're on about, and doing so in the name of the tradition, the folk process, or because source singers did it etc. etc. Do I really take liberties? Phrasing maybe (largely determined by chronic asthma) but saving the odd thing I've supplied myself, I'm a bit of a stickler for tunes. Accompaniments are a different matter - in the words of The Great Beast, do what thou wilt.

with the implication that that means two wholly separate things.

There is a point where Traditional Singers have intersected with The Revival, but not to the extent where it wasn't clear what was going on. The Revival pretty much invents & determines Folk as a cultural concept, even The Tradition to a certain extent, which owes both it's taxonomy & taxidermy to The Revival. To be honest though, I don't lose sleep over any of this.