Bob,you say the folk revival almost completely failed to contribute new material to the traditional repertoire.
Wrong.1 sweet thames flow softly ,2.Dirty old town,3 fiddlers green.4.Ring of Iron.5.Whitby whaler 6.Fields OF athenry[now sung by football fans].6 Reynardine.7 .Song for Ireland.8Wild Rover,9 willie mcbride.and so on on on.
It is not an irrelevancy,because it has enabled traditional musicians/singers like Walter Pardon,and many others to have a platform to perform,to enable singers like Walter who were only singing at home,to pass on their music in live performance to others.
   the music people of like OSCAR WOODS has influenced revivalist performers like Katie Howson,Rod Stradling,Flowers and Frolics,SuffolkBell and HoreshoeBand, Syzewll Gap
In AMERICA Roscoe Holscomb,played little Birdie to Pete Seeger[Traditional musician to Revivalist]PETE asks him what tuning hes in.
immediately interaction and influence takes place.

. the revival cannot be seperated from the tradition,the two are intertwined.