I'll repeat this again here: it's very likely he wasn't fired for trying to have a discussion. It is more likely he was fired because he did so by propagating gender stereotypes and doubling-down on those stereotypes (his suggestions for how to improve diversity essentially were just context-specific extensions of these stereotypes), which both almost certainly reduced his credibility as a coworker to the point that he could not be effectively managed or productive when assigned to work with others. The author glides right past the point in her article when she notes his improper application of findings about averages.

It's possible to have a discussion about these issues today. It's not rational to give special preference and excessive leeway to discussion that isn't actually fact based (and is in many ways based on nothing related to facts).