Earlier quoted context omitted.
If the view is that some of the people you will soon be boss of are not deserving of the same civil rights as everybody else, then that is entirely relevant to his job. Because those employees would have a reasonable fear of discriminatory treatment.
...but they haven't had a fear of discriminatory treatment since he's...a fucking founder of mozilla and worked at the company for 15 years and lead many projects. If there was a fear of discriminatory treatment, we would've heard about it much sooner.
"We haven't detected X, ergo X doesn't exist" is an obviously false notion. It's false even in the same situation, but it's even more obviously wrong in a different one. As CTO, he would have had a hard time making a bigoted technical decision. But as CEO, he's in charge of all sorts of stuff where a subtle bias could be expressed, and there's no longer an executive above him who could hold him accountable.