Kurtzman does confirm Klingons will be a part of the show; more specifically a “Klingon hybrid species who are several of our main characters.”

And then we have this, seen on TrekCore’s Bluesky:

Gina Yashere in grey alien makeup, with horns protruding along her face. She is wearing a red Starfleet uniform with unique patterning. A close-up of the patterning reveals the Klingon Empire symbol.

Kling’Hadar?