"It's important I think to understand that the NLRB isn't saying that it's unlawful to write the Damore memo."

Well, they did call what Damore wrote "sexual harassment" and "discriminatory", and sexual harassment is illegal and violates EEO, so that is basically saying that what he wrote is unlawful:

"The Charging Party’s use of stereotypes based on purported biological differences between women and men should not be treated differently than the types of conduct the Board found unprotected in these cases. [His] statements about immutable traits linked to sex—such as women’s heightened neuroticism and men’s prevalence at the top of the IQ distribution—were discriminatory and constituted sexual harassment, notwithstanding [his] effort to cloak comments with “scientific” references and analysis, and notwithstanding “not all women” disclaimers."