I had one do this before it decided to hose the coral, mine hosted an elegance. I believe someone referred to it as "house cleaning" before they start to host. Sadly mine decided to eat the tips of my elegance and died about 4 days later, but in that 4 days she hosted the elegance nicely.
As long as the fish isn't eating it, I would say the house cleaning theory is happening and will possibly host the nem soon.
GL