https://www.cnet.com/news/star-trek-discovery-will-bring-spock-aboard-for-second-season-comic-con/

Star Trek: Discovery will bring on the franchise's most famous Vulcan for its second season. 

Executive Producer Alex Kurtzman confirmed that Spock would appear when the show comes back in January. But a sizzle reel shown before the crowds at a San Diego Comic-Con panel suggested Spock wouldn't right away, and that he appears to be linked to mysterious red bursts that serve as the central mystery of the season.