The email thing is the strongest evidence she provides, but obviously, a doubting mind can find other reasons that her husbands email would get responses but hers wouldn't.
We do know, however, that African Americans are greatly under represented in tech, in startups and in VC. There are many interlocking reasons for this, and its not unreasonable to expect that racism, whether conscious or unconscious, is one of them. (Why should tech, uniquely in American society, be immune from racism?). Because there are so many interlocking reasons, it's easy for each individual link in the chain of tech to deflect blame to the other links (business can blame the pipeline, colleges can blame the high schools, high schools can blame the financial structures etc etc etc).
So, is it reasonable to expect individual VCs to make a stand against racism instead of doing what comes naturally to them? (trying desperately to make money). Not really!
However, I do think it's reasonable to expect, that VC's who make big pronouncements about what their firm is going to do to combat racism should be expected to follow through with it! And guess what, given all the interlocking problems that prevent black people from founding companies, VC's probably aren't going to be able to follow through on that mission by relying on business as usual of warm intros only, five minute pitch reviews, blow off emails.
Just level with us. We are all adults. Just say, I'm not actually that interested in explicitly helping black founders, I just want to keep trying to make money the way I've been doing it. Conversely, if you do give juicy quotes to the press, then be prepared to walk the walk.