Yes, Dwarves never forget a Grudge. They also don't forget that the Grudges were declared avenged with the death of the Phoenix King Caledor II and the taking of the Phoenix Crown of Aenerion as a trophy. Nor do they forget that those Grudges were against the Ten Kingdoms of Ulthuan, not against what was at the time a rebellious Elven colony that has since completely split from the Asur, both politically and culturally. There's distrust, sure, but not outright hatred. Even the tabletop rules explicitly say they have the 'Hatred' rule for Orcs and Goblins and Skaven, but not Elves.