That is a huge win, however I think it is understandable that he has not come forward, after all that is a lot of money and he could become the victim of criminals and scammers so he is probably worried about it, where I live you can send your legal representative to get the prize money for you, the lottery will know your name and who you are but your identity will be protected from public scrutiny, so I do not know if the winner can do this to avoid all the attention of the media.
I wouldn't send someone to represent that amount for me. I'll take the amount and get to visit personally since it's huge money that's you're about to claim. Although it's possible to have a representative we're talking about huge money in here and you don't trust anyone with that amount.
I don't know if that is granted if there is a representative to claim the prize, as I know you are personally going there as a winner of the prize.
That's a problem because once there are greedy people who know your identity that you have won a huge amount, it is easy for them to find ways how to get your money, blackmailing or even kidnapping someone of your loved ones in exchange for money.
If you see, most are prefer to become anonymous if they will win in the lottery, hiding your identity is something safe in my opinion, than publicly shouting that you have won on lottery.