Sorry if my comments are not to particular respondants, but if interested you can figure them out.
Yes, the Gows and others included a lot of claimed, and not claimed, tunes. As a result, when the Society publishes tunes, they should list Gow if Gow, and Traditional (Gow), if traditional but Gow is our oldest source. Child did not write any of the Child Ballads either, and I assume that most of them have no known authors or sources prior to those from whom he got them. We still refer to them as "Child 76a", etc.
The real point is that these tunes did not just jump from a folk fiddler playing an ancient tune to our publications. So we should always give credit to someone.
Yes, the Society is picky. In fact, I feel they are two picky in a lot of areas (especially where they are wrong). At the same time, the authority of the Society rests in the quality of its publications, and this means it would be wrong not to give credit, especially when the sources are so available.
I would even go backwards when we republish our dance books, and correct reference errors from the past. So if in 1930, we said "from an old MS," and now we know that it was "Jamieson", then we should say so. If the Society has not kept a file of correspondence dealing with its published dances, by dance and tune, it is about time they started.