When the expansion launches, each character of level 60 or above will receive a relic chest to get you started in the new system with a choice of three core relics (exact number subject to change). Additional core relics will not be account bound and can be crafted and shared between players

I appreciate they listened and are now giving one box per char instead of one per account.

As for legendaries:

Legendary relics will be introduced to Guild Wars 2: Secrets of the Obscure during one of the quarterly releases in 2024. These prestigious relics will offer the convenience of freely swapping between the various relic effects. Players who have already crafted legendary runes will be compensated with significant progress toward unlocking legendary relics. In fact, each of the seven legendary runes you create will unlock further progress toward these relics. We’ll be able to share more details when we are closer to the launch of legendary relics next year.

Seems reasonable, tho I'll wait for the full list of requirements and what kind of progress is unlocked before we can say it's "significant".