Title of PCGamer's article is misleading, they want a court order to do it. Proof of death is not enough.
"In general, your GOG account and GOG content is not transferable. However, if you can obtain a copy of a court order that specifically entitles someone to your GOG personal account, the digital content attached to it taking into account the EULAs of specific games within it, and that specifically refers to your GOG username or at least email address used to create such an account, we'd do our best to make it happen. We're willing to handle such a situation and preserve your GOG library—but currently we can only do it with the help of the justice system."
They have to do that anyway. Court orders overrule a company's policies in most (all?) legal systems.