TLJwiki
TLJwiki

Benrime Salmin, who informs April of much regarding magic lore, is also the last in a long line of Seers. She describes a Seer as "someone who can tell something about people, about events, about the past and the present and the future, just by looking at you", and gives her identity as one in an explanation of why she knows April is what the Dark People call a Wave.

This would seem to imply that the Dark People as a race are Seers.