That's right. They will be carried on his statement at zero value.
I had a similar situation. I had a stock many years ago and the company went out of business. The stock was shown on my statement to be valued at 7 cents (total for all shares) for many years and then Zero. I asked my broker what it would take to get it off the statement and was told that there was a way to dispose of it but I would have to pay commission. I decided not to as the item wasn't a problem.
This thread prompted me to look at my positions and I found that it was no longer listed. I looked up my statements and found the following entry last month:
NON-TRANSFERABLE SECURITY
REORG- REMOVE
NON-TRANSFERABLE SECURITY;
NO AGENT IN PAST 6 YEARS
Auto Reorg#249323|REMOVE
WORTHLESS
So it was finally removed at no cost to me after so many years.
There was never a tax issue for me because it was in my IRA.
My point is that the OP's relative can take the loss but doesn't really have to address his portfolio if that's too much of a hassle.

