https://wccftech.com/new-the-witcher-3-easter-egg-discovered-seven-years-after-the-games-release/

A new The Witcher 3 Easter Egg has been discovered in the game, almost seven years since its release in 2015.

The Easter Egg has been discovered by xLetalis, and it involves Vivienne, a character that appears in the Blood and Wine expansion. In one of the expansion's quests, the character is half turned into a bird, and when Geralt offers to remove the curse, he warns her that she may only live as long as the bird she has been turned into. If the player meditates for seven years after completing the quest, Vivienne can be found dead inside Yennefer's room in Kaer Trolde.