Clients of a nationwide staffing agency that allegedly honored company requests not to refer black workers for temporary gigs whiffed in their bid for an early exit from a proposed class action accusing them and the agency of racial bias.

No direct contractual relationship existed between the five workers who filed the lawsuit and the seven client companies, but that doesn’t mean the employees and other potential class members lack standing to sue the companies under 42 U.S.C. § 1981,...