The heroic version of the chest for the evoker tier set, Weyrnkeeper’s Timeless Raiment, appears to be using an older version of the model which attempted a plunging neckline and no halter top. Every other version of this set has a halter top which intersects the plunging neckline aspect, but it looks like when this update was made to the set appearance you guys missed applying it to the heroic set. The issue also only affects the appearance on female character models.
Here’s a comparison pic with the normal set and heroic set side-by-side. Only the heroic set has the chest appearance shown here.
https://imgur.com/a/6KoEDcj