This post from September 23, 2026. https://news.blizzard.com/en-us/article/24307383/get-to-know-the-world-of-warcraft-forever-legacy-system states that

“Legacy Challenges work similarly to achievements in other versions of World of Warcraft but are focused specifically on character progression. There are sixty-five Legacy Challenges in total organized into six different categories. Each challenge completed earns you one Legacy Point. These points are Battle.net account-wide and available to all your non-Hardcore characters."

지피티 의견
이 문구라면 배틀넷 계정 전체 공유를 의미한다고 해석하는 것이 자연스럽습니다.
“These points are Battle.net account-wide and available to all your non-Hardcore characters.”

정확히 해석하면 다음과 같습니다.
Battle.net account-wide: 배틀넷 계정 전체에 적용
available to all your non-Hardcore characters: 해당 배틀넷 계정에 속한 모든 비하드코어 캐릭터가 이용 가능