I wonder how useful models like this actually are. A vortex of superfluid helium sounds like it might have weird and interesting properties, but what can those properties really tell us about black holes? Sure, they might exhibit some analogous behavior, but it just seems like a stretch to use this as a model.
Then again, "it's only a model", and if it could possibly give indications of new properties to search for, I guess it's worth doing?