Came up in a thread over on nano-reef as well, at least one member over there claimed to know someone who actually has these in their system - supposedly kept under the edge of the rock work in the shade and in a very low flow area. Someone who works for a wholesaler and receives coral shipments also stated that they come into the market about once a year or so, and that they should be coming in here sometime soon. Beyond that, on all the boards I visit, I've never seen anyone vender or otherwise who is willing to post that they have them - for growout or otherwise. If someone still has these in captivity, they are not talking about it, they certainly aren't selling them, and I have seen any recent pictures in quite some time.
I did see someone post up a picture of what a vender was calling a soprano, but it wasn't.