What is "DEI-related discrimination at work?" No one knows, including the EEOC.
Late yesterday, the EEOC released two new policy documents aimed at eliminating "unlawful DEI" in the workplace: What You Should Know About DEI-Related Discrimination at Work and What To Do If You Experience Discrimination Related to DEI at Work (the latter even available as a poster-sized PDF).
The most revealing line appears in the opening sentence of the "What You Should Know" document:
"Diversity, Equity, and Inclusion (DEI) is a broad term that is not defined in Title VII of the Civil Rights Act of 1964."
Of course it's undefined, because DEI is not illegal.