That’s sanctions evasion and those companies will be very wary in providing services to any close family of a sanctioned person. My guess is that these people’s SOs, children and their SOs are similarly banned, and that siblings, parents and “close associates” have to provide way more documentation when opening bank accounts than you and I.
In it he specifically mentions that family cannot buy stuff for you because that is a crime if they are in the US or are US nationals, and that your direct family is banned from entering the US (p 4). He does not specifically state whether his family are sanctioned or not but he says that is a risk when he talks in general terms on page 7 about the impacts of the sanctions regime for other judges. Perhaps he is simply not married himself.
Either way, for some reason the news coverage didn’t include these parts of the letter, maybe they didn’t read the whole thing.