I’ve done a bit of searching about this and have found a couple of answers for you .
They will survive ok without them
They will still wave their arms about as if they still got them ( sounds like a song , wave you’re hands in the air like you just don’t care )
Sometimes they put them down somewhere just before they shed and pick them back up after ( so long as they can remember where they left them )
Also you can buy another Pom Pom crab and he will pinch one of that .
That’s about all I can find at the mo hope this helps