It seems that those recordings have been available for a long time. I've visited the site at least half a year ago.

Most of those recordings are complete, but the Miscellaneous Recordings 1950-1990 part only have 45-second excerpts for each session. Some early historical recordings of Tom Paxton and Bob Dylan from 1961 can be found there. We can only hope the full recordings can be put on the website someday.