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.
This is not just proving that you're dead, it's proving that the court thinks it's transferable. These are very different statements