I'm not a bitcoin user who is I'm generally a strong believer in privacy and I think the other article went to far (particularly in personal/family details). Having said that there is a legitimate interest for those who do hold bitcoin in anyone who holds a significant portion of the bitcoins as their actions could massively shift the value of their holdings. Owners of signficant stakes of public companies have to be declared for this type of reason.

The interest in the transaction (and information about related holdings) is to me reasonable and relevant given this individual is believed by some to have a massive quantity of coins from very early mining.