This is the first I heard that the musicians who are still alive have to get paid (not their heirs?). Did she mean musicians who worked on the show (first time I've heard of such an issue for anything, aside from Huckleberry Hound), or the musicians associated with the songs (which is ridiculous, unless the original musicians are the ones who wrote the songs)?
For a few years fans have speculated that the issue could be one or more of the guest stars, but they didn't say anything about guest stars being an issue.