a little more info would help
like - applying for 485 or RFE issued etc.
also, no - they probably wont be required , but I would advise them to get on the case and start inquiring into getting a duplicate (I know its takes forever in some places - all the more reason to start ASAP)
with BCIS, you never know what they want to see or when or why.
but most probably - it should not hold them back in any sense.