From what I’ve read, they don’t taste very good due to what they eat. So they probably won’t get eaten. However it went on to say that some shrimp could shred them in an attempt to eat them.
It’s a valid concern. You could lose one/some till it learned they taste bad. However I have never read a first person report saying someone witnessed this happening.
From personal experience after introducing thirteen into my 70G tank, several were still vulnerable if something were so inclined after 24 hrs. However, I did’t have anything in the tank at the time that would molest them.
It took three months, but I couldn't be happier with the results.